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This study establishes a comprehensive correlation among structural, electrical, and dielectric analyses of fluorine-doped tin oxide (FTO) nanoparticles. The nanoparticles were synthesized through the modified sol–gel method under ethyl supercritical conditions. The investigation into the electrical transport, influenced by the microstructure and grain size of FTO nanoparticles, prompted an exploration of charge carrier transport mechanisms and the impact of doping on this behavior. Both structural and electrical analyses were performed on the samples. The x-ray diffraction results reveal a tetragonal rutile structure in the nanoparticles, as validated by Raman analysis. Particle size and strain values were determined using the Williamson–Hall method, complemented by morphological observations using transmission electron microscopy images. Electrical studies revealed semiconducting behavior in all samples, with conductivity analyzed using Jonscher's law. The small polaron hopping and correlated barrier hopping process models are appropriate for describing the conduction process in the prepared sample. The observed behaviors of the imaginary components of impedance (Z″) and modulus (M″) signify a dielectric relaxation phenomenon within the sample, with activation energies closely matching those derived from the conductivity study. The results strongly suggest that our samples hold great promise for future electronic device applications. [ABSTRACT FROM AUTHOR]

The conductivity and electric modulus formalism in tellurite-modified lithium borate glasses with composition (100–x) − (33.35Li2O–66.65B2O3) − (x)TeO2, (x = 0, 5, 10, 15, 20 and 25 mol%) have been prepared. Electric modulus, relaxation mechanism and conductivity parameters were investigated to understand the dielectric properties of the glass matrix in the temperature range between 403 and 583 K, and the frequency range between 100 Hz and 5 MHz. The experimental data of ac conductivity was fitted to Jonscher’s power law. The parameters like dc conductivity (σdc), frequency exponent (S) and crossover frequency (WH) were extracted. The conductivity of the glass matrix was found to exhibit anomalous increasing behaviour with TeO2 content. The decreasing trend in the values of the frequency exponent with the temperature rise demonstrates the correlated barrier hopping mechanism in the conduction process. The electric modulus data fitted to Davidson–Cole model and Kohlrausch–Williams–Watts model have revealed nearly the same values of β (Kohlrausch exponent), which depict the conductivity relaxation process. Other electrical parameters such as bulk resistance (Rb), capacitance (Ao) and stretching exponent (n) were also extracted by fitting the impedance data to the R-CPE model using Zview software. The dc conductivity of lithium boro tellurite glasses was found to follow Arrhenius behaviour and the corresponding activation energy was determined (0.5847–1.0004 eV). [ABSTRACT FROM AUTHOR]

This study focuses on the preparation of lithium diphosphate compound LiCeP2O7 via conventional solid-state reaction. Analysis using the Rietveld refinement of the X-ray diffraction pattern reveals that the sample adopts a monoclinic structure at room temperature. Surface morphology is further examined through SEM. Additionally, complex impedance and electrical modulus spectroscopy analyses indicate the presence of non-Debye-type relaxation behavior. The direct current (dc) conductivity exhibits Arrhenius behavior, with activation energies of 0.94 eV in region I and 1.21 eV in region II, indicating thermally activated lithium-ion conduction. The thermal behavior of the exponent parameter "s" suggests a transition in the conduction mechanism from large polaron tunneling to small polaron tunneling that occurs at 533 K. Electric modulus studies confirm that the ionic conduction relaxation process is thermally activated and exhibits a spread of relaxation time. Understanding the ionic conduction mechanism will facilitate the design of efficient ionic conductors for battery applications. [ABSTRACT FROM AUTHOR]

Herein, we report on the post-annealing temperature effect on the transport behavior of p-CuO/Al Schottky barrier diodes. In addition, the transformation of phase from Cu4O3 to CuO phase was studied. Copper oxide thin films were grown on soda lime glass substrates, and post-annealing temperature's influence on the films' structural, chemical, morphological, and electrical characteristics was comprehensively examined. X-ray diffraction study revealed the development of polycrystalline tenorite phase (CuO) on annealing. Raman analysis also confirmed the formation of the tenorite phase (CuO) at higher annealing temperatures (400 °C and 500 °C). XPS study revealed the occurrence of the Cu4O3 phase for room temperature deposited sample and CuO phase at the higher annealing temperature. Using current–voltage analysis, the Chueng model, and the thermoelectric emission model, the Schottky behavior between the metal and semiconductor were investigated. The fabricated diode showed a rectification ratio of 103 at ± 2 V, with the barrier height ranging from 0.84 to 1.12 eV due to different annealing treatments. The attributes of the power law were employed to elucidate space charge-limited conduction and the process of tunneling across the density of interface traps in p-CuO/Al Schottky diodes. This study provides valuable insights into the behavior of the p-CuO/Al Schottky junction, enhancing our understanding of its characteristics. [ABSTRACT FROM AUTHOR]

Solid-state polymer electrolyte system that relies on an Iota carrageenan/Acacia gum blend and ethylene glycol as plasticizer incorporated with LiNO3 has been synthesized using the solution cast technique. The structural characterization has done by X-ray diffraction and Fourier transform infrared (FTIR) analysis. FTIR deconvolution reveals that ion–ion interaction analysis and the free ion and contact ion percentage. The electrolyte with 30 wt% LiNO3 (IAN30) has the higher conductivity as 1.77 × 10−3 S cm−1, activation energy as 0.02 eV and ion transport number as 0.999. The non-Debye property of polymer electrolytes is confirmed by studies on the frequency dependence of dielectric and, dielectric loss tangent parameter β. UV spectra of IAN30 also confirms the reduction in band-gap. IAN30 is used for the fabrication of Electric double layer capacitor (EDLC) and Electrochemical cell. There are no redox peaks in the Cyclic voltammetry response through its entire potential range for EDLC behavior. From the galvanostatic charge/discharge studies of prepared symmetrical capacitor, discharge time and specific capacitance (Cs) values are calculated as 16s and 22 F/g respectively. [ABSTRACT FROM AUTHOR]

In this study, calcium titanate (CaTiO3) doped (0, 15, 25 and 35%) polyaniline (PANI) composites in the presence of dodecylbenzene sulphonic acid (DBSA) were successfully synthesized by the means of in-situ emulsion polymerization of aniline monomer. The structural, morphological and optical characterization of as-prepared composites were determined using X-ray diffraction (XRD), field effect scanning electron microscopy, Fourier-transform infrared spectroscopy, UV–vis analysis, and electronic conductivity was determined using two-point probe method. The structural analysis confirms that PANI–DBSA is amorphous, but sharp peaks present in XRD patterns in composites are of crystalline nature. The morphological study reveals efficacious integration of CaTiO3 particles into the PANI–DBSA matrix. Further, the integration of CaTiO3 remarkably reduced the optical bandgap (2.7–2.2 eV) by making composites with PANI–DBSA. Room temperature alternating current conductivity was found to obey universal power law and correlated barrier hopping was found most appropriate model to describe the sample's charge transport mechanism. With the increasing wt% of CaTiO3, the dielectric permittivity and loss both varied according to the interfacial polarization law of Maxwell–Wagner. Moreover, the I–V graphs showed augmented electrical conductivity of composites with an increase in CaTiO3 particle content than that of pure PANI–DBSA. This is a simple way by which PANI–DBSA/CaTiO3 composites having low optical bandgap, high electrical conductivity and permittivity may be fabricated for a widespread technological application. [ABSTRACT FROM AUTHOR]

The effect of Sr2+ doping on electrical conductivity and dielectric constant was studied in Y2 − xSrxNiMnO6 (YSNMO). Rietveld refinement of XRD data showed the coexistence of monoclinic (P21/n) and rhombohedral (R ) as major and minor phases, respectively. Impedance analysis of YSNMO was performed to investigate the presence of various electro-active regions, electrical conduction mechanisms and the origin of the colossal dielectric constant in wide temperature (83-303 K) and frequency (40 Hz-6 MHz) ranges. An equivalent circuit model (RgCg)(RgbQgb)(ReQe) has been proposed to correlate the electrical properties. The Rg and Rgb obtained using ZView fitting revealed the semiconducting nature of the sample. The transition in the conduction mechanism from variable range hopping to small polaronic hopping was observed at about 213 K. DC bias measurements, which followed the Mott-Schottky law, confirmed the existence of non-Ohmic electrode contact. The dielectric spectra of ceramic were described using the modified Cole-Cole equation. The frequency dependent ac conductivity was investigated with the Jonscher's power law. [ABSTRACT FROM AUTHOR]

Perovskite oxide BaNi0.5Mn0.25Fe0.25O3 was successfully synthesized using a sol–gel method. Structural refinement analysis has been performed to investigate the details of the crystalline structure which was found to be a rhombohedral system at room temperature with the space group R 3 ¯ C . Crystallite size, lattice strain, density and porosity parameters were also calculated. The morphology and the elemental composition were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Raman scattering spectroscopy has been performed in order to study the vibrational modes and the various bond formations of the synthesized sample. The study of the magnetic properties shows a ferro-paramagnetic transition (FM–PM) at the curie temperature. The electrical behavior of this double perovskite was also studied using complex impedance spectroscopy. Electrical conduction follows Jonscher's power law, and the conduction mechanisms are identified. The variations of the real and imaginary parts of impedance according to the frequency and temperature show the presence of a relaxation phenomenon in the sample, and it is thus a potential candidate for various technological applications in microelectronics and energy storage. [ABSTRACT FROM AUTHOR]

A better reconciliation of haze pollution and economic growth has become the social consensus in China. The development of China's economy and air quality will be significantly impacted by its efforts to create high-speed rail (HSR). Based on panel data from 265 prefecture-level cities in China from 2003 to 2019, this paper investigates how the opening of HSR affects the spatial mismatch of haze pollution and economic growth by using the spatial mismatch index model, multi-period difference-in-differences (DID) model, and intermediary effect model. We find that the spatial mismatch in China has an overall decreasing trend. And its spatial agglomeration is dominated by low levels. Further empirical analysis shows that HSR opening can effectively restrain the spatial mismatch. Even after some robustness tests and endogenous treatment, the conclusion is still valid. In addition, population density, FDI, and industrial structure are also explicit factors affecting the spatial mismatch. Second, there is significant heterogeneity in the impact. This is reflected in the fact that HSR opening can suppress the spatial mismatch of service-oriented cities and the eastern region, while other cities and regions have no noticeable effect. Third, spatial transfer of haze pollution (STHP) and balanced development of economic growth (BEG) are two important conduction paths for the opening of HSR to affect the spatial mismatch. Specifically, HSR opening can constrain the spatial mismatch by inhibiting STHP and BEG. Based on the above findings, recommendations related to promoting a better harmony between haze pollution and economic growth are proposed. [ABSTRACT FROM AUTHOR]

In this research paper, the [C13H16N2]5(BiCl6)3Cl compound was synthesized, by slow evaporation, at room temperature. It was analyzed by X-ray diffraction, thermal analysis and impedance spectroscopy techniques. The phase transition at T = (400 ± 5)K was evidenced by DSC measurements and confirmed by the electrical study. The electrical measurements were performed in a wide interval of frequency (40–107 Hz) and temperature (300–440 K). The AC conductivity dependence on angular frequency was found to obey the Jonscher's universal power law described by σ AC ω , T = σ DC (T) + B T ω s (T , ω) . Besides, the AC electrical conduction in the prepared material was explained by two theoretical models related to a hopping transport mechanism: the non-overlapping small polaron tunneling (NSPT) model in phase I and (III) and the correlated barrier hopping (CBH) mechanism in phase (II). DC data were found to obey Arrhenius law with activation energies 133 meV and 1.85 eV in agreement with AC measurements and the frequency-dependent maxima ωmax of the imaginary part of modulus. The Nyquist plots were well fitted to an equivalent circuit model taking into account the contribution of grains and grain boundaries. Furthermore, dielectric permittivities were shown to be consistent with the Havriliak–Negami relaxation model. [ABSTRACT FROM AUTHOR]

The polycrystalline sample of LaBaFe1.2Mn0.8O6 was synthesized by sol–gel method. Preliminary analysis of room-temperature X-ray data pattern of the sample confirms the formation of a single-phase compound in rhombohedral crystal system with the space group R 3 ¯ C. Detailed studies of dielectric and impedance spectroscopy complex with frequency at various temperatures confirmed the existence of relaxation phenomenon in the material. Studies of electrical properties show a strong correlation with the microstructure and resistive properties of the material. The electrical transport shows the existence of a non-exponential conductivity relaxation in the material. For different temperatures, the variation of the real part of the permittivity as a function of frequency suggests that the material is a relaxor. Furthermore, the temperature evolution of direct current conductivity indicates that the compound has a semiconductor property. CBH is the most appropriate conduction model. This sample has significant electrical and dielectric qualities; it has a high permittivity and low dielectric loss, making it suitable for technical applications such as capacitors in the electrical area. [ABSTRACT FROM AUTHOR]

In this study, we have proposed and analyzed a theoretical model for NO2 gas sensors. We have developed a realistic model for variation in sensor response as a function of the gas concentration, temperature, humidity, and sensing film thickness and derived a general expression relating to the sensor response. Tungsten trioxide (WO3)-based gas sensors were adopted because of their physical and chemical properties, low cost, and ease of preparation. Superior sensing characteristics were obtained for 0.42 eV activation energy, where the device exhibited a sensor response of 14.41 toward 1 ppm NO2 gas concentration at room temperature. To validate the applicability of the proposed model, a comparative analysis was conducted, and an excellent match was obtained between the proposed model and experimental data. The analysis carried out in this work offers a feasible and promising approach for a wide variety of sensing materials. [ABSTRACT FROM AUTHOR]

In the last decade, the diketopyrrolopyrrole (DPP)-based molecular semiconductors received significant prominence for its ability to build ambient stable donor–acceptor type organic materials for numerous microelectronics applications, especially in organic thin-film transistors and photovoltaics. This research article demonstrates the charge transport properties of 3,6-bis(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2,5-dihexadecylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione[DPP(PhNMe2)2] in single layer device structure prepared by thermal evaporation technique in the frequency and temperature range of 102–106 Hz and 133–273 K, respectively. An initial impression of Nyquist plot suggests metal-like behaviour as the impedance increases with an increase in temperature. Semicircle in Nyquist plot suggests Debye-type relaxation. This result has been explained mathematically and fitted equivalent circuit (contact resistance + parallel combination of resistance and capacitance) of device. Resonance frequency have been estimated by the Nyquist plot and crosschecked by Joncher’s Power Law. The frequency exponent ‘s’ is estimated by Joncher’s Universal Power Law and it further shows that charge transport mechanism in the device is quantum mechanical tunnelling. These analyses indicate the existence of Poole–Frenkel effect and explains the charge carrier mobility dependence on the applied field in the studied temperature range. [ABSTRACT FROM AUTHOR]

A change in current-voltage (I-V) behaviour of the p-Si-based diodes as a result of 4 MeV proton-irradiation to the fluence of 1016 p/cm−2 was investigated using I-V techniques at room temperature. The diode I-V behaviour changed from normal exponential to ohmic behaviour after proton-irradiation, indicating that proton introduce generation-recombination (g-r) centres, defect levels that are positioned in the middle of the band gap of Si. These centres recombine mobile charge carriers, thereby, reducing the concentration of carriers through the space charge region (SCR). The reduction of the concentration results in an increase in material resistivity as confirmed by the increase in series resistance after proton-irradiation. Furthermore, a change in diode parameters such as saturation current (Is), ideality factor (η), Schottky barrier height (ϕb), and series resistance (Rs) due to the irradiation is also investigated. A change in diode parameters and conduction mechanism due to proton-irradiation presented in this work is of great importance for an ongoing study on radiation-induced damages and radiation-hardness of Si material. [ABSTRACT FROM AUTHOR]

We report an investigation of the structural, morphological, the ac-dc electrical, magnetic, and Mössbauer spectroscopy properties of 20MnFe2O4-80SiO2 nanocomposite prepared using a one-step and facile auto-combustion approach. XRD pattern shows the formation of MnFe2O4 nanocrystallite without any crystallization of the SiO2 phase. However, the presence of a secondary phase of the nanosized α-Fe2O3 particles was also detected. The morphological analysis showed aggregation of polygonal magnetic nano-crystallites dispersed non-uniformly in a silica matrix. The dc electrical measurements performed on a wide range of temperatures from 120 to 400 K showed the semiconducting nature of the nanocomposite. The temperature dependence of dc conductivity could be perfectly fitted to the nearest neighborhood hopping model with activation energy, ΔENNH, of 0.45 eV. The Nyquist plots demonstrated a nonmonotonous thermally activated trend and non-Debye relaxation behavior. An equivalent circuit was successfully fitted to the complex impedance spectra. The variation of both grain and grain boundary conductivities as a function of temperature exhibited three distinct regions, semiconducting-metallic-semiconducting with different activation energies over the measured temperature window. The provided description of such behavior is further advocated by the ac conductivity and dielectric modulus studies. VSM measurements revealed that the nanocomposite magnetic behavior deviates from the ideal non-interacting superparamagnetic picture, due to the presence of α-Fe2O3 nanocrystalline impurities and relatively intensive exchange interactions between ions. Mössbauer spectra showed the presence of Fe3+ ions with sixfold environment and also confirmed the existence of a sextet related to α-Fe2O3 with a quantity of about 20% out of magnetic components. Fe3+ superparamagnetic doublets were also found within the fitting procedure. [ABSTRACT FROM AUTHOR]

Complexes of Cu (II) and Co (II) with (4-[(2,4-dihydroxy-benezylidene)-amino]-1,5-dimethyl-2-phenyl-1,2-dihydroxo-pyrazol-3-one have been synthesized and characterized. The alternating current conductivity (σac) and dielectric properties of Cu (II) and Co (II) complexes were investigated in the frequency range 100Hz–5MHz and temperature range 295–475 K. The values of the thermal activation energies of ligand, Cu (II) and Co (II) complexes were calculated at different frequencies. The behaviors of the dielectric constants with both frequency and temperature were investigated. σac was found to follow semiconducting behavior with frequency. The charge carrier's conduction mechanisms were suggested. The overlapping large polaron tunneling mechanism was adopted for complex X1 while for ligand and complexes X2, X3 correlated barrier hopping is the dominant conduction mechanism. [ABSTRACT FROM AUTHOR]

The temperature-dependent electrical resistivity of the Ni-doped CoSb3 system (Ni= 0, 1, 3, and 5 at.%) was carried out to identify the conduction mechanism at the different temperatures. The samples were prepared by solid-state reaction and characterized by x-ray diffraction (XRD) and Raman spectroscopy. The XRD pattern confirms the CoSb3 phase for the pristine sample while the NiSb2 compound is identified as an impurity phase for Ni content > 3 at.%. Five out of eight Raman active modes are evident in the pristine sample indicating the formation of the Skutterudite phase. Ni in CoSb3 acts as an electron donor and hence decreases the resistivity approximately seven times at low temperature. The temperature-dependent Seebeck coefficient exhibits an increase in magnitude with doping concentration and a negative value is observed for all the samples indicating the formation of n-type skutterudite. The results of the thermoelectric properties are promising due to the significant increase in power factor (282 µW/mK2) for the doped sample. The temperature-dependent electrical resistivity analysis reveals that in the high-temperature regime (285–400 K), there is a dominance of thermally activated band conduction while in the lower temperature region (< 280 K), the hopping conduction is dominant. The detailed analysis of the temperature variation of resistivity shows that in the temperature range from (190–280 K), nearest-neighbor hopping (NNH) dominates, whereas, in the lower temperature region, Mott's variable range hopping (VRH) is the dominant conduction mechanism. T dev , at which VRH occurs is 180 K for pristine CoSb3 and is found to decrease with Ni doping concentration and is attributed to the increase in the density of states at the Fermi level. [ABSTRACT FROM AUTHOR]

The physical properties of the sodium diphosphate ε Na4P2O7 ceramic were investigated by X-ray diffraction (XRD), morphology, dielectric, and electrical measurements. Rietveld refinements of X-ray diffraction (XRD) data show that the compound crystallizes in the orthorhombic structure belonging to the space group Pmmm. Not only were the AC conductivity of our compound carried out at different temperatures and frequencies, but also its electrical modulus was evaluated, as well as the dielectric relaxation. On the other hand, the behavior of frequency exponent s of AC conductivity as a function of temperature is reasonably well interpreted by the correlated barrier hopping (CBH). In terms of CBH model, the values of maximum barrier height, hopping distance, and density of localized states are determined and discussed. A correlation between electrical and structural properties was also studied. Besides, the present results provide insights into the exploitation of sodium diphosphate ε Na4P2O7 as a promising cathode material for application in sodium-ion batteries. [ABSTRACT FROM AUTHOR]

This paper reports thickness-dependent structural, morphological, optical, and electrical conduction mechanism of room temperature electron beam evaporated 2D WSe2 thin films on glass substrate. The thickness of the WSe2 films was varied from 100 to 400 nm. XRD results showed the fact that the WSe2 films are crystallized in a hexagonal structure. The nanostructure nature is verified from morphological studies. It was found that the microstrain decreases, while the crystallite size rises as the thickness of WSe2 film increases. The thickness-dependent optical constants and energy bandgap was studied using spectroscopic ellipsometry (SE). The refractive index and extinction coefficient dispersion curves of WSe2 film with various thicknesses display two strong absorption peaks A and B below 800 nm at 580 nm and 770 nm, which are belong to excitonic absorption features. Further, the results illustrate that the optical constants and optical bandgap of thin WSe2 films are strongly correlated with the film thickness. In addition, the electrical conduction mechanism in different temperature regimes is explained in terms of Arrhenius activated thermal conduction, Mott's variable-range hopping (VRH), and Seto's grain boundary effect models. The most interesting finding is that the film exhibits wide absorption coefficient (106 cm−1) and energy gap value closely matches the solar spectrum, making it an excellent candidate for photovoltaic materials as an absorber layer. [ABSTRACT FROM AUTHOR]

Double perovskite oxide with general formula LaBa0.5Ag0.5FeMnO6 (LBAFMO) has been prepared by the sol–gel-based Pechini method. To study and compare its electrical properties, impedance spectroscopy was carried out in the temperature ranging from 200 K to 340 K and frequency range from 100 Hz to 1 MHz. At room temperature, x-ray diffraction analysis revealed the compound to be single phase and to crystallize in the cubic system in space group Pm-3m. The imaginary part of the impedance (Z″) as a function of frequency indicated non-Debye model relaxation. Impedance data in a Nyquist plot (Z″ versus Z′) was used to determine an equivalent circuit. The complex impedance of LBAFMO revealed the presence of grain and grain-boundary contributions. The alternating-current (AC) conductivity as a function of frequency was interpreted by applying Jonscher's law to determine the activation energy. Modulus analysis revealed the occurrence of a relaxation process supplemented by a conduction phenomenon. [ABSTRACT FROM AUTHOR]

Amino acid added sodium ion-conducting Polyvinyl Alcohol (PVA), Polyvinyl Pyrrolidine (PVP) blend polymers are sythesised as thick films using solvent casting method. Prepared films are subjected to its characterization through FTIR, XRD and dielectric analysis. The electrical conductivity properties of SPEs are done for various frequencies and temperatures through an AC dielectric analysis. The ionic conductivity of 6.03 × 10–5 S/cm has been obtained as maximum for the higher concentration of aminoacid in blend polymer at room temperature. The way of increasing electrical conductivity due to temperature seems to obey the Arrhenius behaviour. The magnitude of the electric modulus peak has been observed for temperature variation and suggested the multiplicity phenomena in relaxation. Relaxation-activation energies calculated from electric modulus and tangent analysis are found to be same. From the cyclic voltammetry analysis, the electrochemical performances are observed. The fabricated electrochemical cell shows the potential window in the range of 2.16 V. [ABSTRACT FROM AUTHOR]

Lithium bromide ionic salt dispersed with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/polyvinylpyrrolidone (PVP) blend polymers have been prepared by solution casting, and used as an electrolyte for the improvement of solid-state lithium batteries. The structural and molecular bond identification studies of polymer electrolytes have been studied and confirmed using x-ray diffraction (XRD) and Fourier-transform (FTIR) analysis. Electrical characterizations of solid polymer films have been studied by AC impedance analysis. The higher conducting sample follows the Arrhenius relationship, and the conductivity based on the dielectric constant obeys modified Arrhenius behavior. The ion transport mechanisms coincide with the correlated barrier height (CBH) model, and the ionic diffusion was verified through the tunneling mechanism. Optical properties for the prepared polymer electrolytes have been investigated using ultra violet (UV) spectrum analysis. From this analysis, the higher conductivity polymer electrolyte has a minimum band gap at 4.14 eV. [ABSTRACT FROM AUTHOR]

Indium sulfide thin films with different amounts of silver doping were deposited by spray pyrolysis. The samples were tested as potential photocatalysts by degrading methylene blue (MB) dye aqueous solution under the effect of light. Samples were prepared using precursors with Ag/In ratios of 0 at.%, 4 at.%, and 6 at.%, corresponding to a measured and normalized Ag concentration in the films of 0.0 at.%, 1.4 at.%, and 2.3 at.%, respectively. Scanning electron microscopy revealed that the surface of the films was homogeneous and compact. Within the energy resolution of dispersive x-ray spectroscopy, the films were revealed to be stoichiometric with an S/In ratio of 1.50 ± 0.05. The films exhibited semiconductor behavior, and the best direct-current (DC) conductance was achieved for the film with 1.4 at.% Ag doping. Changes in the Ag concentration led to the activation of different conduction mechanisms, from correlated barrier hopping (for the undoped and for 1.4 at.% Ag-doped film) to overlapping large-polaron tunneling (for the 2.3 at.% Ag-doped film). After immersing the samples in MB solution and exposing them to visible light for 270 min, a significant decrease of the MB absorption was observed. The lowest absorption (and thus highest photodegradation efficiency) was measured for the solution containing the sample with 1.4 at.% Ag doping, showing a photodegradation efficiency of 83%. Considering their performance and relatively low manufacturing cost, such In2S3:Ag films could contribute to the solution of environmental problems related to wastewater via photodegradation of contaminants under illumination by sunlight. [ABSTRACT FROM AUTHOR]

In this work, the ceramic compound α-KYP2O7 (α-KYP) was synthesized by a standard reaction in the solid-state, at high temperature. The morphology and structure of the sample were analyzed by scanning electron microscope and X-ray diffraction, respectively. The result of the X-ray diffraction revealed that all diffraction peak's positions agree well with the reflection of an orthorhombic structure (Cmcm space group) without additional peaks. Regarding the differential scanning calorimetry, an irreversible phase transition located at T4 = 667 K (Heating) and three reversible phase transitions were observed at T1 = 490/463 K, T2 = 603/587 K, and T3 = 633/617 K (heating/cooling). The optical properties were studied by UV–Vis absorption spectroscopy. By looking directly at the UV absorption measurements and using the Tauc model, we found that the direct optical band gap is equal to 3.39 eV. In particular, the title compound also exhibits semiconductor and optical properties. The real and imaginary parts of the function of the impedance and conductivity have been studied over a wide range of temperatures and frequencies. From the Nyquist plots, we observe the existence of a grain and grain boundaries effect in the material. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model. The angular frequency dependence of the conductivity was interpreted using the developed Jonscher relation. The conduction of the studied sample is ensured by K+ ions' hopping in the tunnels and its mechanism was discussed. From these results, it can be concluded that this material can be used for different high temperature applications. [ABSTRACT FROM AUTHOR]

The crystalline samples of La0.67Ca0.33Mn1-xNixO3 (x = 0, 0.05, and 0.1) manganites were prepared by conventional solid-state reaction method. The analysis of X-ray diffraction spectra revealed that all the prepared samples are single phased in nature and have acquired orthorhombic structure with space group Pbnm. Temperature-dependent dc resistivity measurements infer metallic nature of the samples in the lower temperature region (T > 50 K) where metal to insulator transition (TMI) occurs at temperature 238 K, 204 K, and 187 K for x = 0, 0.05, and 0.1, respectively. For the temperature below 50 K, a kind of transition from paramagnetic insulator to the ferromagnetic metallic phase was observed in all the materials. The application of magnetic field of 8 T indicates the shift of TMI toward the higher temperature region with high reduction in resistivity due to suppression of any thermal agitations present. The resistivity data analysis for conduction mechanism above 50 K infers that the grain/domain boundary scattering processes play a dominant role in the the metallic region. However, the analysis of the region below 50 K infers that weak localization effect is the responsible factor in conduction phenomena. Isothermal at 300 K for magnetoresistance study conveys that the pristine La0.67Ca0.33MnO3 manganite exhibits larger MR effect with rise in magnetic field compared to doped ones. [ABSTRACT FROM AUTHOR]

In this perspective research, methyl violet 6B, a nanocrystalline dye, is exploited as an impregnating material for improving the absorption and photoconductivity characteristics of polyvinyl alcohol, PVA. The PVA-MV composite thin film's structure and morphology revealed a uniform smooth surface with 9.7 nm root mean square roughness. The optical absorption of PVA thin film is enhanced after the dye incorporation and exhibited an energy gap modification from 4.36 to 1.75 eV. Moreover, we fabricated an Ag/PVA-MV/p-Si/Al MIS Schottky diode and investigated its electrical characteristics in dark. The heterojunction's microelectronic parameters such as ideality factor, reverse saturation current, barrier height, rectification ratio are estimated and found to be 2.5, 6.4 nA, 0.78 eV, and 8795.2 at 3 V, respectively. A significant quasi-saturated reverse photocurrent with obvious sensitivity for light intensity variations is detected. The fabricated photodetector exhibited responsivity, specific detectivity, and signal-to-noise ratio ~ 2.622 mA/W, 6.46 × 109 Jones, and 407.9, respectively. [ABSTRACT FROM AUTHOR]

In this study, NaCo2O4 nanofibers were synthesized via an electrospinning technique. The uniformity and size of these nanofibers were optimized as a function of polyvinylpyrrolidone (PVP) concentration. NaCo2O4 nanofibers were characterized by TG–DTA, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, energy-dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). No crystallinity was observed in the nanofibers when calcined at 100 °C, whereas at 600 °C predominatly γ-phase of NaCo2O4 nanofibers with good crystallinity was achieved. Analysis of XRD and SEM results revealed that PVP concentration and calcination temperature played an important role in the formation of the desired crystalline phase, size, uniformity and porosity of NaCo2O4nanofibers. Temperature-dependent current voltage (IV) characteristics demonstrated the presence of an ohmic region (lower voltage) followed by space charge limited current conduction (SCLC) at intermediate voltage. The presence of surface traps and imperfections can be the possible reason for the SCLC transport. The average value of the Seebeck coefficient "S" was 128 μV/K near room temperature. [ABSTRACT FROM AUTHOR]

We measured the electrical conductivity of tremolite over a range of pressures (1.0, 1.5, and 2.0 GPa) and temperatures (648–1373 K). At temperatures lower than 1173 K, the electrical conductivity of tremolite was ~ 0.001 S/m, but once the dehydroxylation reaction took place at 1173 K, we observed a significant increase in the electrical conductivity. The electrical conductivity continued to increase until it reached its maximum value of ~ 1 S/m at a temperature of 1373 K, which we attributed to dehydroxylation in the tremolite samples. The electrical behavior was altered by the physical breakdown of the tremolite structure, rather than the oxidation process. The decomposition of tremolite resulted in the creation of diopside, enstatite, and quartz. To explain some anomalous conductivity measurements, we propose that iron-free amphibole experiences a dehydroxylation mechanism that differs from the dehydroxylation mechanism observed in iron-bearing amphiboles. Our conductivity analyses indicate that the observed increase in the electrical conductivity in deep subduction regions (at depths of ~ 180 km) is driven by the dehydroxylation of tremolite and by the mixing of lherzolite and tremolite in the upper mantle. Using our data and previously published temperature gradient data, we were able to extrapolate reasonable electrical conductivity values for the surface and interior of Venus. [ABSTRACT FROM AUTHOR]

Lead-free Ba0.97La0.02Ti1−xNb4x/5O3 (abbreviated as BLT and BLT0.98Nb0.016) ceramics were grown using the molten-salt method with filtration as well as evaporation technique. A correlation investigation between the morphological, structural, and electrical properties of the system was carried out using impedance spectroscopy at various frequencies (40–106 Hz) and temperatures (500–600 K). In the present work, average grain size estimated from the microstructure was ~ 2700 nm. Phase composition was established by the Rietveld refinement, which confirms that our compounds have a single phased nature and crystal structure. They have a tetragonal Perovskite structure with a P4/mmm space group, without any secondary phases. Z′ and Z″ values of impedance decreased with increasing Nb concentration. The EIS data displayed an approximately perfect semi-circle at high temperature in the complex plane plot as well as a practically ideal non-Debye peak shape in the spectroscopic plot. The electrical conductivity decreased with increasing niobium amount. The frequency dependence of conductivity plot has been found to obey the universal Jonscher power law. The correlated barrier hoping was established to be the most suitable theoretical model to elucidate the conduction process. These results could help improve the electrical properties of Ba0.97La0.02Ti1−xNb4x/5O3 compounds and understand the relationship between the structure and the electrical properties. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the AC electrical properties of chloroindium phthalocyanine (ClInPc) in order to evaluate its conduction mechanism. For this purpose, sandwich devices of ClInPc with aluminum electrodes (Al/ClInPc/Al) were fabricated. The measurements indicated that the capacitance and loss factor increased by an increase in the temperature and decreased by an increase in the frequency. In addition, measurement results obtained are consistent with Goswami and Goswami's model. AC conductivity is confirmed by the equation σ(ω) = AωS, which is commonly used for charge transport with hopping or tunneling mechanism. In this study, the conduction mechanism was studied with correlated barrier hopping at the frequency range of 100 Hz–1 kHz and overlapping large-polaron tunneling models at the frequency range of 1 kHz–100 kHz. Furthermore, the activation energies of the device were achieved as a function of frequency. The structure of the ClInPc thin film was determined by x-ray diffraction and scanning electron microscopy images. Additionally, by using the UV analysis of the ClInPc thin film, the optical band gap was obtained as 2.9 eV and the absorption bands Q and B were observed in the visible region. [ABSTRACT FROM AUTHOR]

The electrical behavior of the high-field induced diffusive metal (HFIDM) is demonstrated in ceramic–metal composite film deposited by aerosol deposition (AD) method. To verify the effect of HFIDM, electrical properties for non-composite and metal-composite films are analyzed. The obtained results clearly demonstrate that HFIDM in composite film strongly affected its electrical properties such as current level, conduction mechanism, breakdown field, and resistance. These changes are attributed to the displacement and migration of HFIDM under electric field, leading to the noticeable variations in its electrical properties. These findings can provide a strong roadmap for AD-based applications using ceramic-HFIDM composite film. [ABSTRACT FROM AUTHOR]

We report on the study of In substitution for Mn on the magnetic and transport properties of layered manganese oxides La0.7Er0.05Sr0.15Ca0.1Mn1−xInxO3 (0 ≤ x ≤ 0.30) synthesized via sol-gel method. For all the samples, all peaks are satisfactorily indexed in the rhombohedra structure with R 3 ¯ c space group. Magnetic data, under a magnetic field of 0.05 T, revealed that our compounds exhibit a continuous (second-order) transition from a ferromagnetic (FM) to a paramagnetic (PM) state upon decreasing the temperature. Also, magnetic entropy change and relative cooling power for magnetic field variation were predicted. Then, we have fitted the experimental data of resistivity using non-linear curve fitting, a typical mathematical function (Gauss function). This function can describe the carrier transport behavior of manganites as a function of temperature around the electrical phase transition. The obtained results were discussed. These predicted parameters agree with the experimental data. [ABSTRACT FROM AUTHOR]

Cesium–zinc orthophosphate (CsZnPO4) was prepared by a solid-state method. X-ray powder diffraction at room temperature confirmed the phase formation of the synthetized compound in the monoclinic system (P21/a space group). Infrared and Raman spectroscopies showed the presence of PO43− anion and its vibrations. Regarding the differential scanning calorimetry, three reversible phase transitions were revealed. The first is of a second-order type located at T1 = 520/503 K (heating/cooling), while the second and the third ones are of a first-order type located at T2 = 544/520 K (heating/cooling) and T3 = 585/577 K (heating/cooling). The detected phase transitions with calorimetric measurements were confirmed by average normalized change (ANC) and electrical conductivity study. The conduction of the studied sample is assured by Cs+ ions' hopping in tunnels and its mechanism was discussed. [ABSTRACT FROM AUTHOR]

In this work, Li2BaP2O7 doped 1% Eu3+ was prepared by a solid-state reaction method and characterized by X-ray diffraction technique, IR, and impedance spectroscopy. Rietveld refinement of the X-ray diffraction pattern suggests the formation of the single-phase desired compound with monoclinic structure at room temperature. Electrical properties were studied using complex impedance spectroscopy in the frequency range of 200 Hz–5 MHz and temperature range of 598–724 K. The temperature dependence of the bulk and grain boundaries' conductivity was found to obey the Arrhenius law with activation energies Eg = 0.79 eV and Egb = 1.85 eV respectively. Temperature dependence of the power law exponent s strongly suggests that tunneling of large polaron is the dominant transport process. The obtained results are compared with the undoped Li2BaP2O7 sample and correlated with structural analysis. Doping pyrophosphate compound by Eu3+ presents better conductivity and electrical properties. [ABSTRACT FROM AUTHOR]

The diphosphate RbGdP2O7 compound has been synthesized by the conventional solid-state reaction method and characterized by X-ray powder diffraction, Raman spectroscopy and impedance spectroscopy. The title compound crystallizes in the monoclinic system with P21/c space group. The AC electrical conductivity was measured in a frequency range from 200 Hz to 1 MHz and temperature range 480–580 K. Impedance plot revealed the presence of two contributions at different temperatures associated with grain and grain boundary. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model based on the ZView software. The temperature dependence of these contributions is found to obey the Arrhenius law with activation energies 0.42 eV and 0.32 eV, respectively. The alternating current (AC) conductivity of grain contribution follows the universal Jonscher's power law. The temperature dependency of frequency exponent 's' shows that the correlated barrier hopping model (CBH) is the most responsible mechanism for AC conduction in the investigated compound. The theoretical fitting between the proposed model and the experimental data showed good agreement. [ABSTRACT FROM AUTHOR]

We report the crystal growth as well as transport properties of Co added Bi2Se3 (Co0.1Bi2Se3) single crystals. The values of the lattice parameters for pure and Co added sample were nearly the same. The Raman spectroscopy displayed slightly higher Raman shift of corresponding A1g1, Eg2, and A1g2 vibrational modes for Co0.1Bi2Se3, and the resistivity curves with and without applied magnetic field show a metallic behavior. Both the crystals were subjected to magneto-resistance (MR) measurements under applied fields of 14 T. The value of MR is found to decrease from about 380% (5 K, 14 T) for Bi2Se3 to 200% for Co0.1Bi2Se3. To elaborate the transport properties of pure and Co added Bi2Se3 crystals, the magneto-conductivity is fitted to the HLN (Hikami-Larkin-Nagaoka) equation, and it is found that the charge conduction is mainly dominated by surface-driven WAL (weak anti-localization) with negligible bulk WL (weak localization) contribution in both crystals alike. The MH curves of Co0.1Bi2Se3 crystal at different temperatures displayed a combination of both ferromagnetic and diamagnetic behavior. On the other hand, the electron paramagnetic resonance (EPR) revealed that pure Bi2Se3 is diamagnetic, whereas Co orders ferromagnetically with resonating field around 3422 Oe at room temperature. The calculated value of Lande "g" factor is around 2.04 ± 0.05. Summarily, the short letter discusses the interesting magneto-conductivity and complex magnetism of Co in Co0.1Bi2Se3. [ABSTRACT FROM AUTHOR]

We report the magneto-conductivity analysis at different temperatures under a magnetic field of up to 5 T of a well- characterized Bi2Te3 crystal. Details of crystal growth and various physical properties including high linear magneto-resistance are already reported by some of us. To elaborate upon the transport properties of Bi2Te3 crystal, the magneto-conductivity is fitted to the known Hikami-Larkin-Nagaoka (HLN) equation and it is found that the conduction mechanism is dominated by both surface-driven weak anti-localization (WAL) and the bulk weak localization (WL) states. The value of HLN equation coefficient (α) signifying the type of localization (WL, WAL or both WL and WAL) falls within the range of − 0.5 to − 1.5. In our case, the low-field (± 0.25 T) fitting of studied crystal exhibited a value of α close to − 0.86 for studied temperatures of up to 50 K, indicating both WAL and WL contributions. The phase coherence length (lφ) is found to decrease from 98.266 to 40.314 nm with increasing temperature. Summarily, the short letter reports the fact that bulk Bi2Te3 follows the HLN equation and quantitative analysis of the same facilitates to know the quality of studied crystal in terms of WAL to WL contributions and thus the surface to bulk conduction ratio. [ABSTRACT FROM AUTHOR]

Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism. [ABSTRACT FROM AUTHOR]

In the present work, biopolymer electrolyte films based on MC doped with NH4Br salt and plasticized with glycerol were prepared by solution casting method. Fourier transform infrared (FTIR) spectroscopy analysis confirms the interaction between MC, NH4Br, and glycerol. X-ray diffraction (XRD) explains that the enhancement of conductivity is affected by the degree of crystallinity. This result is verified by field emission scanning electron microscopy (FESEM). For unplasticized system, sample containing 25 wt% of NH4Br possesses the highest ionic conductivity of (1.89 ± 0.05) × 10−4 S cm−1. The addition of 30 wt% glycerol increases the conductivity value up to (1.67 ± 0.04) × 10−3 S cm−1. The conduction mechanism was best presented by the correlated barrier hopping (CBH) model. The linear sweep voltammetry (LSV) and cyclic voltammetry (CV) result confirms the suitability of the highest conducting electrolyte to be employed in the fabrication of electrochemical double layer capacitor (EDLC). [ABSTRACT FROM AUTHOR]

The contradiction between environmental protection and economic development has become an important issue in China. Environmental regulation, as a vital content of public regulation, is an effective approach to rectify market failure. Thus, studying the impact of environmental regulation on the coordinated development between environment and economy is beneficial to design the most suitable environmental management system for Chinese government. Based on the theory of regulation economics and industrial organization, this paper incorporates environmental regulation policy in the traditional SCP paradigm and analyzes the conduction mechanism of market structure and market behaviors on the coordinated development between environment and economy. With the empirical analysis, we find the existence of an EKC curve, which means that tightening the environmental regulation is an effective means of guaranteeing economic growth and optimizing environmental quality. Eventually, we point out the problems existing in China’s current environmental regulation system and design a new one which is more suitable for the current economic development stage of China. [ABSTRACT FROM AUTHOR]

The Na superionic conductor (NASICON) NaNbAlPO compound was prepared by the conventional solid-state reaction method. The formation of single-phase material was confirmed by X-ray diffraction studies, and it was found to be a hexagonal phase at room temperature. The electrical conductivity was measured in the frequency range from 200 Hz to 5 MHz and temperatures between 573 and 773 K using impedance spectroscopy technique. The obtained results were analyzed by fitting the experimental data to the equivalent circuit model. The analysis of Nyquist plots has revealed the contribution of three electrically active regions corresponding to the bulk mechanism, distribution of grain boundaries, and electrode processes. Besides, the frequency dependence of the conductivity is interpreted in terms of Jonscher's law. Temperature dependence of the power law exponent s strongly suggests that the non-overlapping small polaron tunneling (NSPT) model is the dominant transport process. The variation of the imaginary part of the complex modulus as a function of angular frequency at several temperatures shows a double relaxation peak suggesting the presence of grains and grain boundaries in the sample. An analysis of the dielectric constants ε″ and loss tangent tan ( δ) with frequency shows a distribution of relaxation times. [ABSTRACT FROM AUTHOR]

A novel series of divalent transition metals (Cu, Co and Ni) polymer complexes of azo ligand named 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-8-hydroxyquinoline (Q) have been synthesized. The azo quinoline ligand (Q) and polymer complexes are characterized by various physicochemical techniques. The thermal properties of the ligand and its isolated polymer complexes are studied using thermogravimetric analysis. The physicochemical investigations elucidate that the azo ligand acts as a neutral bis(bidentate) ligand. The polymer complexes are found to be octahedral geometry. The change in the ac electrical conductivity, loss tangent and dielectric properties are studied upon heating in temperature region 298-550 K and frequency ranging from 0.1 to 100 kHz, moreover, the mechanism of conduction is determined. The electrical conductivity studies indicate that the ligand (Q) and polymer complexes have the semiconducting behavior. The correlated barrier hopping is the dominant conduction mechanism for all samples. [ABSTRACT FROM AUTHOR]

In the present work, the effects of temperature and frequency on the ac electrical and dielectric properties of polycrystalline NdFeNiO, prepared by solid-state reaction method, are investigated. From the impedance spectroscopic measurements, three relaxation processes are observed, which are related to grains, grain boundaries and electrode-semiconductor contacts in the measured temperature and frequency range. For NdFeNiO sample, the applicable equivalent circuit model is ( R Q )( R Q )( R Q ) in the measured temperature range. Decrease in resistances and relaxation times of the grains and grain boundaries with temperature confirm the involvement of thermally activated conduction mechanisms. With the increase in temperature, the relaxation frequencies increase for all three processes and the conduction mechanism changes from Mott variable range hole hopping to adiabatic small polaronic hole hopping in this material. The permittivity of grains is from 8 to 10, while the high permittivity observed at higher temperatures is extrinsic (due to Maxwell-Wagner type polarizations), which is primarily due to the formation of different Schottky barriers. The grain boundaries, ceramic surfaces and electrode-semiconductor contacts mainly contribute in the colossal value of permittivity of NdFeNiO. The ac conductivity plots show the positive values of the 'dσ/d T' which indicate that the charge carriers are localized. The results of conductivity signify that the delocalization of charge carriers augment with increase in the temperature in this system. [ABSTRACT FROM AUTHOR]

The Rb(HSeO)(HPO) compound was prepared and its thermal behavior and electric properties were investigated. The thermogravimetry (TGA) analysis and the differential scanning calorimetric (DSC) show the presence of a structural phase transition of the title compounds at 374 K which is confirmed by the variation of fp and σ as a function of temperature. The complex impedance of the Rb(HSeO)(HPO) compound has been investigated in the temperature range of 295-453 K and in the frequency range 209 Hz-1 MHz. The impedance plots show semicircle arcs at different temperatures, and an electrical equivalent circuit has been proposed to explain the impedance results. The circuits consist of the parallel combination of bulk resistance Rp and constant phase elements CPE in series with fractal capacity CPE. The frequency dependence of the conductivity is interpreted in terms of Jonscher's law. The conductivity dc follows the Arrhenius relation. The near value of activation energies obtained from the analysis of modulus, conductivity data, and circuit equivalent confirm that the transport is through the ion hopping mechanism, dominated by the motion of the H proton in the structure of the investigated materials. [ABSTRACT FROM AUTHOR]

The electrical conductivity of pyroxene andesite was in situ measured under conditions of 1.0-2.0 GPa and 673-1073 K using a YJ-3000t multi-anvil press and Solartron-1260 Impedance/Gain-phase analyzer. Experimental results indicate that the electrical conductivities of pyroxene andesite increase with increasing temperature, and the electrical conductivities decrease with the rise of pressure, and the relationship between electrical conductivity ( σ) and temperature ( T) conforms to an Arrhenius relation within a given pressure and temperature range. When temperature rises up to 873-923 K, the electrical conductivities of pyroxene andesite abruptly increase, and the activation enthalpy increases at this range, which demonstrates that pyroxene andesite starts to dehydrate. By the virtue of the activation enthalpy (0.35-0.42 eV) and the activation volume (−6.75 ± 1.67 cm/mole) which characterizes the electrical properties of sample after dehydration, we consider that the conduction mechanism is the small polaron conduction before and after dehydration, and that the rise of carrier concentration is the most important reason of increased electrical conductivity. [ABSTRACT FROM AUTHOR]

The Ti/Y modified CuO-based negative temperature coefficient (NTC) thermistors, CuYTiO (TYCO; y = 0.01, 0.015, 0.03, 0.05 and 0.07), were synthesized through a wet-chemical method followed by a traditional ceramic sintering technology. The related phase component and electrical properties were investigated. XRD results show that the TYCO ceramics have a monoclinic structure as that of CuO crystal. The TYCO ceramics can be obtained at the sintering temperature 970°C-990°C, and display the typical NTC characteristic. The NTC thermal-sensitive constants of TYCO thermistors can be adjusted from 1112 to 3700 K by changing the amount of Ti in the TYCO ceramics. The analysis of complex impedance spectra revealed that both the bulk effect and grain boundary effect contribute to the electrical behavior and the NTC effect. Both the band conduction and electron-hopping models are proposed for the conduction mechanisms in the TYCO thermistors. [ABSTRACT FROM AUTHOR]

In the present study, the potential of methyl cellulose (MC) as biopolymer electrolyte (BPE) will be studied extensively by means of conductivity and the conduction mechanism. BPE films based on MC doped with ammonium iodide (NHI) salt were prepared by solution-casting method. X-ray diffraction (XRD) explains that the conductivity enhancement of the electrolytes is affected by the degree of crystallinity. Field emission scanning electron microscopy (FESEM) analysis shows the difference in the electrolyte's surface with respect to NHI. On addition of 40 wt.% of NHI, the highest room temperature conductivity of (5.08 ± 0.04) × 10 S cm was achieved. The temperature dependence relationship for the salted electrolyte was found to obey the Arrhenius rule where R ∼1 from which the activation energy ( E ) was evaluated. The dielectric study analyzed using complex permittivity ε* for the sample with the highest conductivity at elevated temperature shows a non- Debye behavior. These salted electrolytes follow the correlated barrier hopping (CBH) model. [ABSTRACT FROM AUTHOR]

This work focused on the metal-oxide-semiconductor (MOS) capacitor and extremely thin silicon-on-insulator (ETSOI) p-type MOS field-effect transistor ( pMOSFET) with laminated hafnium and titanium oxide (Hf-Ti-O) thin films as gate dielectric. The electrical behavior of the MOS capacitor shows that the capacitor with Hf-Ti-O gate dielectric has high performance with low equivalent oxide thickness (EOT, ~0.77 nm), small hysteresis (Δ V, ~4 mV), and gate current density of 0.33 A/cm at V = V − 1 V. The dominant conduction mechanism of the Hf-Ti-O thin film (25°C to 125°C) was Schottky emission at lower gate voltage (−0.8 V to −0.2 V) and Fowler-Nordheim (F-N) tunneling at higher gate voltage (<−0.8 V). An ETSOI pMOSFET with 25 nm gate length ( L) also exhibited good electrical properties with switch ratio of 3.2 × 10, appropriate threshold voltage of −0.16 V, maximum transconductance ( G) of 2.63 mS, drain-induced barrier lowering of 53 mV/V, and subthreshold swing of 65 mV/dec. [ABSTRACT FROM AUTHOR]

Hydrous minerals are important water carriers in the crust and the mantle, especially in the subduction zone. With the recent development of the experimental technique, studies of the electrical conductivity of hydrous silicate minerals under controlled temperature, pressure and oxygen fugacity, have helped to constrain the water distribution in the Earth's interior. This paper introduces high pressure and temperature experimental study of electrical conductivity measurement of hydrous minerals such as serpentine, talc, brucite, phase A, super hydrous phase B and phase D, and assesses the data quality of the above minerals. The dehydration effect and the pressure effect on the bulk conductivity of the hydrous minerals are specifically emphasized. The conduction mechanism of hydrous minerals and the electrical structure of the subduction zone are discussed based on the available conductivity data. Finally, the potential research fields of the electrical conductivity of hydrous minerals is presented. [ABSTRACT FROM AUTHOR]

The charge defective structure in BiCaFeO (CBFO, x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) nanoparticles (NPs) ranging from 140 to 25 nm as well as their relations to band gap and leakage current behavior are investigated. It is demonstrated that Ca doping effectively narrows the band gap from ~2.16 to ~2.02 eV, due to the appearance and accumulation of oxygen vacancy. Subsequently, enhanced electrical conductivity was obtained in these CBFO NPs, which leads to the appearance of a distinct threshold switching behavior in Ca-doped BFO NPs with higher conductivity at room temperature. Possible mechanisms for Ca doping effects on the electric conduction were discussed upon the interplay of NPs' size effect and mobile charged defects on the basis of reduced particle size and the increased density of oxygen vacancy analyzed through X-ray photoelectron spectrum. [ABSTRACT FROM AUTHOR]