Search

In this study, KTa0.55Nb0.45O3 (KTN) thin films were manufactured by using Chemical Solution Deposition (CSD) method with variations in the sintering temperature and were investigated in order to apply their applicability in memory devices. The KTN thin films were made after coating the PZT bufferlayer on Pt/Ti/SiO2/Si substrate. Each layer was dried at 200°C for 5 min to remove any organic materials and pyrolyzed at 400°C for 10 min. Finally, the layers were sintered for 30 min under an oxygen atmosphere, respectively. The pattern of KTN thin films showed a preference to the (100) and (200) orientations. Also, an increase in the sintering temperature caused the KTN crystalline peak intensities to also increase. When looking at the results from the Scanning Electron Microscope and Atomic Force Microscope data, the average grain size and root mean square roughness (Rrms) of KTN thin films were 109~157 nm and about 4 nm, respectively. Typical dielectric dispersion characteristics were observed in which the dielectric constant decreases with an increase of the applied frequency. The specimen sintered at 750°C showed the highest dielectric constant of 769 at 1 kHz.

In this study, K(Ta0.6Nb0.4)O3 thin films were fabricated by sol–gel method and their structural and electrical properties were measured to investigate the applicability for electrocaloric devices. As the thickness of thin films increased, crystallinity was improved. The average thickness of the thin films with a single coating was about 130–140 nm. Dielectric constant, dielectric loss, remanent polarization, and coercive field of the 6 times coated thin KTN films at 30 °C were 4920, 0.492, 18.49 μC/cm2 and 54.7 kV/cm, respectively. As the number of coatings increased, the temperature at which the decrease in remanent polarization began also subsided. Likewise, the rate of change in remanent polarization increased as the temperature became higher. When a voltage of 220 kV/cm was applied to the 3 times coated KTN films, the electrocaloric property was 2.95 °C. When the 3 times coated thin KTN films were at 75 °C, electrocaloric property for a unit electric field was about 1.47 °C.

In this study, Zn1.10CuxMn1.90-xO4 (0 ≤ x ≤ 0.15) systems were prepared through the conventional solid state reaction method. All specimens were sintered in air at 1200 °C for 12 h and cooled at a rate of 2 °C/min to 800 °C, subsequently quenching to room temperature. Structural investigations were carried out using X-ray diffraction patterns and energy dispersive spectrometry. For x ≥ 0.10, formation of a tetragonal phase with a Zn-rich Zn-Cu-Mn-O segregated second phase was observed. In the microstructure, the grain size increased from 5.10 μm to 9.68 μm with an increase in Cu content. The resistivity at room temperature, B-value, responsivity and detectivity of the Zn1.10Cu0.05Mn1.85O4 specimen were found to be 300.2 kΩ·cm, 4665, 0.025 V/W, and 2.12 ×104 cmHz1/2/W, respectively.

Objective: Organophosphate insecticide (OPI) self-poisoning is a major medical problem in many countries. Several studies have demonstrated that the base deficit (BD) is a prognostic tool that is correlated with the severity of injury and predicted mortality, particularly in trauma patients. Here, we aimed to investigate the prognostic significance of BD in OPI poisoning. Methods: This retrospective observational study was conducted between January 1, 2006, and January 31, 2015, at a single emergency department (ED). The BD values were divided into quartiles according to the number of patients: 3 mEq/L or less, 3–5.9 mEq/L, 6–9.9 mEq/L, and 10 mEq/L or greater. Survival at 30 days from ED admission was estimated using the Kaplan–Meier survival analysis. Results: Among 154 patients, 31 died, yielding a mortality of 20.1%. The highest BD quartile (≥ 10 mEq/L) and the 6–9.9 mEq/L group were associated with an increased risk of 30-day mortality. Patients with a BD of 10 mEq/L or greater had a 5.85-fold higher risk of 30-day mortality and patients with a BD of 6–9.9 mEq/L had a 5.40-fold higher risk of 30-day mortality compared to patients with a BD of 3 mEq/L or less. The area under the curves of the BD and the Acute Physiology and Chronic Health Evaluation II score for mortality were 0.748 (95% confidence interval (CI), 0.660–0.835) and 0.852 (95% CI, 0.789–0.915), respectively. Conclusions: This study showed that the BD is a predictor of 30-day mortality in patients with OPI poisoning.

In this study, Ni(MnCu)O (x=0~0.25) specimens were prepared by using a conventional mixed oxide method. All specimens were sintered in air at 1,200℃ for 12 h and cooled at a rate of 2℃/min to 800℃, subsequently quenching to room temperature. We investigated the structural and electrical properties of Ni  (Mn  Cu  )O  specimens with variation of CuO amount for the application of NTC thermistors. As results of X-ray diffraction patterns, all specimens showed the formation of a complete solid solution with cubic spinel phase. The relationship between ln ρ and the reciprocal of absolute temperature(1/T) for the NTC thermistors was shown linearity, which exhibited the typical NTC thermistor properties. With increasing the amount of CuO, resistivity at room temperature, B-value, and temperature coefficient resistance decreased.

In this paper, the BaTiO3/Ni composite films of 10 μm were fabricated by Aerosol deposition. We investigate the dielectric behavior of BaTiO3/Ni composite films with various Ni contents. The BaTiO3/Ni composite film with Ni content of 9.1 vol% has high dielectric constant at 1 kHz (476) due to the percolation effect. This high dielectric constant was attributed to the microcapacitor structures and Maxwell–Wagner polarization. Although the BaTiO3/Ni composite film was fabricated at room temperature, it had a high dielectric constant of 8 times higher than that of raw BaTiO3 film, and showed a very low leakage current. Therefore, BaTiO3/Ni composite films fabricated by Aerosol deposition can potentially be used as embedded capacitors.

For NiMn2O4 systems, the mixed valence of manganese on B-sites arises from the displacement of bivalent cations, such as Ni2+, from A-sites to B-sites which results in a corresponding proportion of Mn3+ cations on B-sites disproportionate to Mn2+ and Mn4+, and the Mn2+ cations move to the A-sites to compensate Ni2+ vacancies. With the assistance of random crystal field fluctuations and the mixed valence of manganese eventually leads to the formation of localized small polarons which accomplish a thermally activated hopping conduction between Mn3+ and Mn4+ cations on octahedral sites. In this study, we have investigated the structural and electrical properties of NixMn3-xO4 system. And, we have comprehensively measured the electrical transport mechanism, the temperature coefficient of resistance and infrared detection performance for the application of infrared radiation detectors.

Background:Acute pesticide poisoning has long been a serious problem as a method of suicide worldwide. This poisoning is a highly fatal condition that requires a rapid and precise diagnosis for adequate treatment. However, various studies on mortality predictor factors have been insufficient for whole pesticide treatments. We hypothesized that the initial plasma anion gap (AG) and base deficit (BD) are reliable prognostic factors.Methods:A retrospective study analyzed 561 patients with a diagnosis of acute pesticide poisoning between January 1, 2014 and June 30, 2017. The initial AG and BD values were divided into quartiles according to the number of patients. Survival at 30 days from admission was estimated using the Kaplan–Meier survival analysis. Receiver-operator characteristic (ROC) curves were drawn, and the areas under the curve for AG and BD for mortality were calculated.Results:Fifty-eight (10.3%) of 561 patients died within 30 days. The highest AG quartile (>22 mEq/L) was associated with an increased risk of 30-day hospital mortality. Compared to patients with an AG less than 14.7 mEq/L, these patients had a 4.18-fold higher risk of 30-day hospital mortality and the highest BD quartile (>7.9 mEq/L) was associated with an increased risk of 30-day hospital mortality. Compared to patients with a BD less than 1.4 mEq/L, these patients had 2.23-fold higher risk of 30-day hospital mortality. The areas under the ROC for AG and BD curve were 0.699 and 0.744, respectively.Conclusions:Initial high AG and BD values could predict mortality and require precise intensive care.

We investigated the annealing effect of CSZT films on Pt and Cu substrates fabricated by aerosol deposition (AD) process. The fabricated films were annealed at 100, 250, and 500 degrees C, and all XRD patterns revealed CSZT phase with a perovskite structure, with the exception of the films on Cu substrates annealed at 250 and 500 degrees C, which presented a CuO secondary phase. The dielectric constant and the dielectric loss of the CSZT films on the Pt substrates were observed to increase slightly as the annealing temperature increased. However, the Cu substrates annealed at 250 degrees C presented lower values. The leakage current of films on the Pt substrate decreased as the annealing temperature increased. On the other hand, the films on a Cu substrate increased as the annealing temperature increased, and these results showed that the films on Cu substrates have inferior properties due to the presence of CuO.

In this study, we fabricated an electrolyte-insulator-metal (EIM) device incorporating a high-k Al2O3 sensing membrane using a porous anodic aluminum oxide (AAO) through a two-step anodizing process for pH detection. The structural properties were observed by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns (XRD). Electrochemical measurements taken consisted of capacitance-voltage (C-V), hysteresis voltage and drift rates. The average pore diameter and depth of the AAO membrane with a pore-widening time of 20 min were 123nm and 273.5nm, respectively. At a pore-widening time of 20 min, the EIM device using anodic aluminum oxide exhibited a high sensitivity (56mV/pH), hysteresis voltage (6.2mV) and drift rate (0.25mV/pH).

In this study, NixMn3-xO4 ceramics were prepared using a conventional mixed oxide method for application in infrared sensors, and the dried powder was calcined at 900?C for 2h. All specimens were sintered in air at 1200?C for 12h and annealed at a rate of 2?C/min to 800?C, subsequently quenching to room temperature. It has been shown that all specimens showed the formation of a cubic spinel phase without any second phase. From the surface micrographs and density results, all specimens showed a high density and low porosity. In terms of the temperature coefficient of resistance (TCR=1/R?dR/dT), all specimens showed values -4%/?C above and the typical NTCR (negative temperature coefficient of resistance) properties, displaying decreased electrical resistance with an increase in temperature. The resistivity of the Ni0.79Mn2.21O4 specimen at room temperature was approximately 2602??cm. The responsivity and detectivity of the Ni0.79Mn2.21O4 ceramics sintered at 1200?C were 4.56?10-3V/W and 2010cmHz1/2/W, respectively. Display Omitted Nickel manganite NixMn3-xO4 ceramics for the application of IR sensorsNixMn3-xO4 systems were prepared by using a mixed-oxide method.The X-ray diffraction patterns confirmed the spinel cubic polycrystalline structure.The temperature coefficient of resistance, all specimens showed values -4%/?C above.The typical NTCR (negative temperature coefficient of resistance) properties

La9.33(Si5V1)O26 ceramics were fabricated by the mixed oxide method for solid oxide electrolytes. La9.33(Si5V1)O26 specimens showed the hexagonal, space group P63 or P63/m, and the unit cell volume increased when the sintering temperature increased. The specimen sintered at 1,400℃ showed the X-ray patterns of the homogeneous apatite single phase without the second phase, such as La2SiO5 and SiO2. The specimen sintered at 1,400℃ showed the maximum sintered density of 4.93 g/cm3. When the sintering temperature increased, the electrical conductivities increased, the activation energy decreased and the values were 7.83×10−4 S/cm, 1.61 eV at 600℃, respectively.

The second-generation selective 5-HT2 receptor antagonists and reuptake inhibitors (SARIs) class antidepressants are known to have fewer cardiovascular side effects than the older ones. However, several case reports showed that trazodone, one of the second-generation SARIs, induces QT prolongation, cardiac arrhythmia, and ventricular tachycardia. Although these clinical cases suggested trazodone-induced cardiotoxicity, the toxicological actions of trazodone on cardiac action potentials (APs) beyond the human ether-a-go-go related gene (hERG) remain unclear. To elucidate the cellular mechanism for the adverse cardiac effects of trazodone, we investigated its effects on cardiac APs and ion channels using whole-cell patch clamp techniques in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and transiently transfected human embryonic kidney cells (HEK293) with cardiac ion channel complementary DNA. Trazodone dose-dependently decreased the maximum upstroke velocity ( Vmax) and prolonged the AP duration, inducing early after depolarizations at 3 and 10 μM that triggered ventricular arrhythmias in hiPSC-CMs. Trazodone also inhibited all of the major ion channels ( IKr, IKs, INa, and ICa), with an especially high inhibitory potency on hERG. These data indicate that the prolonged AP duration and decreased Vmax due to trazodone are mainly the result of hERG and sodium ion inhibition, and its inhibitory effects on cardiac ion channels can be exhibited in hiPSC-CMs.

Objective: Some studies have evaluated the prognostic indicators associated with acute paraquat (PQ) poisoning. In this study, we externally validated the Yamaguchi index, which showed a good prognostic relevance in predicting the outcome of PQ poisoning. Methods: A retrospective analysis of 297 patients was performed. The Yamaguchi index was calculated using the following equation: Eq1 = (K+ × HCO3−)/(Creatinine × 0.088)(mEq/L) against time from PQ ingestion ( T). The patients were divided into three groups: group A: Eq1 > 1500 − 399 × log T, group B: 930 − 399 × log T < Eq1 ≤ 1500 − 399 × log T, and group C: Eq1 ≤ 930 − 399 × log T). Results: The overall mortality rate was 65.3% (194 of 297). The mortality rates of the three groups stratified by the Yamaguchi index were 7.1% (2 of 28), 22.4% (15 of 67), and 87.6% (177 of 202). The area under the receiver–operating characteristic curve for predicting mortality from the external validation of the Yamaguchi index was 0.842 (95% confidence interval: 0.795–0.882). Conclusion: The Yamaguchi index is a reliable prognostic factor and could be helpful in predicting mortality due to PQ poisoning.

In this paper to improve the ionic conduction properties, lanthanum silicate apatite ceramic, which substituted by V ions at Si-site, were fabricated by the mixed-oxide method. And we investigated the structural and electrical properties of specimens with variation of dopants for the application of solid oxide fuel cells. The sintering temperature of specimens decreased from to . As results of X-ray diffraction patterns, all specimens showed the formation of a complete solid solution in a apatite polycrystallin structure. But the specimens doped with more than 1.5mol% showed the second phase, and . The specimen dopants with 1.0 mol% showed the maximum ion conductivity. Ion conducting and activation energy of the specimens were about 1.62 eV at , respectively.

In order to achieve the aerosol deposition (AD) process as a thin film deposition process, the densification mechanism of the AD process was investigated. BaTiO3 films with thicknesses of 0.2, 0.5, and 2 μm on Cu substrates were fabricated using the AD process at room temperature in order to investigate the densification mechanism according to the increased the film thickness; we also investigated the resulting properties, including the microstructure, the electrical properties, and the hardness. As a result, we confirmed that the enhanced hammering effect (which is a densification procedure that works by continuous impaction of ceramic particles onto pre-impacted particles), formed dense BaTiO3 films with greater hardness and decreased leakage current characteristics. Furthermore, we concluded that the BaTiO3 particles, which were sufficiently fractured due to the hammering effect, were important in fabricating the dense BaTiO3 thin films. Therefore, we suggested the two-step deposition method (deposition and etching).

We successfully prepare H 2 Ti 12 O 25 by soft-chemical synthesis using Na 2 Ti 3 O 7 compounds, prepared by Na + /H + ion exchange and heating. Then, a cylindrical hybrid supercapacitor is fabricated by using H 2 Ti 12 O 25 as anode and activated carbon as cathode. The specific capacitance of hybrid supercapacitor using H 2 Ti 12 O 25 is 57 Fg −1 higher than that of hybrid supercapacitor using Li 4 Ti 5 O 12 (38 Fg −1 ). The hybrid supercapacitor using H 2 Ti 12 O 25 exhibit cycle performance with a capacitance retention of 65.3% available for battery application. The energy density is 35 W h kg −1 at a power density of 179 W kg −1 and 4 W h kg −1 at a power density of 5383 W kg −1 . These results show that the H 2 Ti 12 O 25 anode material is a promising electrode material for hybrid supercapacitor.

In this study, YBa2Cu306+x (YBCO) thick films were investigated for their application in uncooled microbolometers. YBCO powders were prepared using the conventional mixed oxide method and were deposited on an SiO2/Si substrate using the aerosol deposition method (ADM) at room temperature. As a result of thermogravimetry and differential thermal analysis (TG-DTA) of YBCO powder, an endothermic peak was observed at approximately 820 °C. The powder was calcined at 880 °C. The deposited film were annealed at 600-750 °C (O2:Ar = 1:1, pO2) and their structural and electrical properties were investigated at varying annealing temperatures. From X-ray diffraction (XRD) results, all films displayed the typical XRD patterns of the tetragonal phase and the second phase was observed. The thickness of all the YBCO thick films was approximately 15.7 µm. As a result of the temperature coefficient of resistance (TCR = 1/R * dR/dT), the YBCO thick films annealed at 700 °C showed the maximum value of -3.1%/°C and all YBCO thick films showed typical NTCR (negative temperature coefficient of resistance) properties, displaying decreased electrical resistance with an increase in temperature.

LiFePO4/C composite powder as cathode material and graphite powder as anode material for Li-ion batteries were synthesized by using the sol-gel method. An electrochemical improvement of LiFePO4 materials has been achieved by adding polyvinyl alcohol as a carbon source into as-prepared materials. The samples were characterized by elemental analysis (EA), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-EM). The chemical composition of LiFePO4/C powders was in a good agreement with that of the starting solution. The capacity loss after 500 cycles of LiFePO4/C cell is 11.1% in room temperature. These superior electrochemical properties show that LiFePO4/C composite materials are promising candidates as cathode materials.

Hydrogen titanium oxide, H2Ti12O25 is prepared by soft chemical method. A fabricated asymmetric hybrid supercapacitor using an AlPO4 modified H2Ti12O25 anode shows electrochemical performance superior to a Li4Ti5O12 anode, including cycling performance. The anode comprised of H2Ti12O25 coated with 3 wt.% AlPO4 shows the energy and power density of 41.1 Wh kg−1, 194.1 W kg−1, respectively, at a current rate of 0.1 A g−1 as well as the highest cycling performance, with 94.1% specific capacitance retained after 1000 cycles at a current rate of 3.0 A g−1. These excellent results are convincing evidence that H2Ti12O25 should be regarded as one of the more promising anode materials.

In this paper, the centre of electrode is suggested for heat conduction. Therefore, the specific reflow soldering process is needed. The comparison of temperature difference among the different areas of ZnO varistors is analyzed. With the nominal surge current, thermal behavior is analyzed. The operation point of temperature for disconnection is proposed. Accordingly, the thermal runaway-preventing ZnO varistors were covered with a fusible alloy, i.e., a thermal fuse, in the process of manufacture, which is expected to ensure there the liability of being resistant to lightning discharge and to ensure stability against thermal runaway in the failure mode. Additionally, it is expected to reduce much more limit voltage than the existing products to which the fuse was separately applied. The thermal runaway-preventing ZnO varistor of the surge protection devices can be widely used as part of the protection provisions of lightning discharge and surge protection demanded in connection with power IT about Green Growth which is nowadays becoming the buzzword in the electric power industry.

The effects of various contents of alumina co-doping on a ceria-based electrolyte were investigated. All samples were sintered at 1500 °C for 10 h. The X-ray diffraction (XRD) patterns showed a fluorite cubic structure. To investigate the surfaces of the Ce 0.8 (Sm 0.5− x Y 0.5 Al x ) 0.2 O 2− δ (CSYA) ceramics by scanning electron microscopy (SEM), the electrical properties of the CSYA ceramics were measured by AC impedance. The optimal values of ionic conductivity and activation energy were reached at x = 0.4 measured at 600 °C. This result indicated that the alumina co-doping improved the electrical and microstructural properties of the ceria-based electrolyte.

In this study, 1 − x (Na 0.5 K 0.5 )NbO 3 – x (Sr 0.5 Ca 0.5 )TiO 3 ceramics were fabricated using the conventional mixed oxide method. The effects of the addition of (Sr 0.5 Ca 0.5 )TiO 3 on the structural and electrical properties of the specimens were investigated for their application in piezoelectric devices. As the results of X-ray diffraction analysis show, all specimens display the typical polycrystalline perovskite structure without the presence of the second phase. Sintered densities increased with an increase in the amount of (Sr 0.5 Ca 0.5 )TiO 3 added and the specimen with 0.08 mol% of (Sr 0.5 Ca 0.5 )TiO 3 added showed the maximum value of 4.54 g/cm 3 . Both average grain size and densification increased with an increase in the amount of (Sr 0.5 Ca 0.5 )TiO 3 . The electromechanical coupling factor, dielectric constant ϵ r , dielectric loss tan δ , d 33 and Curie temperature of the 0.92(Na 0.5 K 0.5 )NbO 3 –0.08(Sr 0.5 Ca 0.5 )TiO 3 specimens doped with 0.08 mol% of (Sr 0.5 Ca 0.5 )TiO 3 were 0.31, 1338, 0.021, 138 and 445 °C, respectively.

We report the brilliant piezoelectric and dielectric properties of (Na0.5K0.5)NbO3 (NKN)-based materials and consider a promising candidate as a lead-free piezoelectric ceramic. However, because of volatile characterization of potassium and sodium oxide, the difficulty of sintering condition of NKN ceramics has been significantly issued. Therefore, we focused on sintering aids. To suppress volatilization and improve the sintering condition, other perovskite type’s compounds and various sintering aids were added to NKN ceramics. We fabricated the 0.98(Na0.5K0.5)NbO3–0.02Li0.04(Sb0.06Ta0.1)O3 (0.98NKN–0.02LST) ceramic by conventional solid-state reaction, and investigated the effects of various sintering aids (Ag2O, CuO, CeO2, MgO, MnO, ZnO) on the piezoelectric, dielectric, and structural properties of the 0.98NKN–0.02LST ceramic. All samples showed more outstanding properties than NKN ceramics. These results indicate that the 0.98NKN–0.02LST ceramics doped with various sintering aids is a promising candidate as a lead-free piezoelectric ceramic.

A cylindrical hybrid supercapacitor was fabricated using Li4−xNaxTi5O12 as an anode and activated carbon as a cathode. Li4−xNaxTi5O12 (0 ≤ x ≤ 0.6) powder was successfully crystallized, and the grain size of Li4−xNaxTi5O12 decreased with increasing Na content. This indicated that Na can enhance the electrochemical performance due to smaller grain size and ionic conductivity. However, excessive Na content causes a distortion of the original Li4Ti5O12 structure during cycling. The hybrid supercapacitor with the Li3.7Na0.3Ti5O12 anode shows similar electrochemical performance to Li3.4Na0.6Ti5O12, and approximately 92% of the maximum cycle performance is retained, even after 5000 cycles at 2.5 Ag−1.

The effects of Sr doping on the electrical properties of Ce 0.75 (Gd 0.95− x Sr x Ca 0.05 ) 0.25 O 2− δ ( x = 0, 0.01, 0.02, 0.03, 0.04, 0.05 mol%) electrolytes thick films were investigated. The samples sintered at 1400 °C for 8 h. X-ray diffraction (XRD) showed typical XRD patterns of a cubic fluorite structure, and the ionic conductivity was examined by AC impedance spectroscopy. From the experimental results, it was observed that Ce 0.75 (Gd 0.95− x Sr x Ca 0.05 ) 0.25 O 2− δ ( x = 0.04 mol%) electrolytes thick film have higher conductivity and minimum activation energy at 600 °C. This is explained in terms of the increased in the oxygen vacancy concentration at the grain boundary.

In this paper, (Ca0.7Sr0.3)(Zr0.8Ti0.2)O3 thin films were fabricated by RF-sputtering at various deposition temperatures from 300 °C to 700 °C to determine the optimal deposition condition. The XRD data confirmed the successful fabrication of crystalline CSZT thin films. Based on the dielectric properties of the fabricated thin films, the optimal deposition temperature was 700 °C, which resulted in a film with a relatively high dielectric constant and low dielectric loss (28.4 and 0.006) (at 1 MHz). Moreover, the CSZT thin film deposited at 700 °C showed stable dielectric properties at microwave frequencies. With increasing deposition temperature, the roughness of the CSZT thin film increased but the leakage current of the CSZT thin film decreased, simultaneously.

In this study, we fabricated anodic aluminum oxide (AAO) membrane by two step anodizing process for pH detection. The structural properties were observed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). Electrochemical measurements of the pH sensor have been performed in capacitance-voltage (C-V) and drift rates. The characterization of AAO membrane exhibited high sensitivity (99.1 mV/pH) at second anodizing time of 4 min.

YBCO thin films on /Si substrate were fabricated by spin-coaing of an alkoxide-derived precursor and heat treatment. The structural and electrical properties of the YBCO films were investigated as functions of annealing temperature at . Although YBCO single phase was not synthesized, dense films of YBCO matrix phase and minor second phases have been successfully fabricated at the annealing temperatures of . Thickness and temperature coefficient of resistance (TCR) of YBCO thin films with annealing temperature of were 0.31 and , respectively.

In this study, (Na0.465K0.465Bi0.07)(Nb0.93Ti0.07)O3 ceramics with MnO2 addition were prepared by conventional mixed oxide method. The effects of MnO2 addition on the structural and electrical properties of the specimens were investigated for the application of piezoelectric devices. As the results of X-ray diffraction analysis, all specimens showed the typical polycrystalline perovskite structure without presence of the second phase. Sintered densities increased with increasing the addition amount of MnO2 and the specimen added with 0.06 mol% of MnO2 showed the maximum value of 4.87 g/cm3. Average grain size increased and densification increased with an increasing of MnO2 contents. The electromechanical coupling factor, dielectric constant, dielectric loss, d33 and Curie temperature of the 0.06 mol% of MnO2 doped (Na0.465K0.465Bi0.07)(Nb0.93Ti0.07)O3 specimens were 0.32, 1309, 0.016, 122 and 465 °C, respectively.

Lead-free 0.98(Na0.5K0.5)NbO3-0.02(Ba0.5Ca0.5)TiO3 (0.98NKN-0.02BCT) ceramics were produced by using a conventional mixed oxide method with sintering temperature from 1080°C to 1120°C and their piezoelectric properties were investigated. The results indicate that the sintering temperature influences the electrical and the piezoelectric properties of 0.98NKN-0.02BCT ceramics. For the 0.98NKN-0.02BCT ceramics sintered from 1080°C to 1120°C, the piezoelectric constant d 33, electromechanical coupling factor k p , remnant polarization values P r and curie temperature T c increased with increase sintering temperature. However, for 0.98NKN-0.02BCT sintered above 1100°C, their values decreased. Piezoelectric properties of d 33 = 210 ρC/N and k p =46%, ferroelectric properties of P r = 16.2 µC/cm2 and dielectric constant ɛ r = 5159 were obtained for specimen sintered at 1100°C for 4 h. Therefore, the 0.98NKN-0.02BCT ceramics are excellent candidate materials for lead-free piezoelectric ceramics.

Uncooled pyroelectric infrared based on semiconducting YBa2Cu3O6+x (YBCO) thin films have been investigated. YBCO precursor solutions were prepared by sol-gel method and YBCO films were fabricated by the spin coating method and structural and electrical properties with variation of annealing temperature were studied. As a result of the differential thermal analysis and thermogravimetry (DTA-TG) analysis, endothermic peak was observed at around 750°C due to the formation of the tetragonal phase. The crystal structure of the YBCO film annealed at 750°C was polycrystalline tetragonal phase. The thickness of all the films was approximately 0.26∼0.31 μm and average grain size of the YBCO film sintered at 750°C was about 60 nm. Temperature resistance coefficient (TCR), responsivity and detectivity of the YBCO film sintered at 750°C were 3.7%/K at room temperature, 14.47 V/W and 7.23 × 106 cm Hz1/2/W, respectively.

Lead-Free ceramics 0.95(Na0.5K0.5)NbO3-0.05CaTiO3-x mol. % Ag2O have been fabricated as a function of the amount of Ag2O content. NKN-CT ceramics showed the highest piezoelectric properties and ferroelectric properties at the 0.5 mol. %Ag2O content. The NKN-CT-Ag2O0.5 mol. % ceramics show a good performance with piezoelectric constant d33 = 221 ρC/N, kp = 0.38%, respectively. The corresponding Curie temperature and remnant polarization reached 370°C and 22.5 µC/cm2, respectively. These results appear that NKN-CTAg2O ceramics are promising candidate materials for lead-free piezoelectric application.

We investigated the annealing effect of CSZT films on Pt and Cu substrates fabricated by aerosol deposition (AD) process. The fabricated films were annealed at 100, 250, and 500 degrees C, and all XRD patterns revealed CSZT phase with a perovskite structure, with the exception of the films on Cu substrates annealed at 250 and 500 degrees C, which presented a CuO secondary phase. The dielectric constant and the dielectric loss of the CSZT films on the Pt substrates were observed to increase slightly as the annealing temperature increased. However, the Cu substrates annealed at 250 degrees C presented lower values. The leakage current of films on the Pt substrate decreased as the annealing temperature increased. On the other hand, the films on a Cu substrate increased as the annealing temperature increased, and these results showed that the films on Cu substrates have inferior properties due to the presence of CuO.

Lead-free 0.98(Na 0.5 K 0.5 )NbO 3 –0.02Ba(Zr x Ti (1− x ) )O 3 (0.98NKN–0.02BZT) ceramics with Zr contents were fabricated by a conventional mixed-oxide method. The results indicate that the Zr/Ti ratio significantly influences the structural, piezoelectric, dielectric, and ferroelectric properties of 0.98NKN–0.02BZT ceramics. For the 0.98NKN–0.02BZT ( x = 0) ceramics sintered at 1090 °C, the bulk density increased as the Zr contents decreased and showed a maximum value at x = 0. The Curie temperature of the 0.98NKN–0.02BZT ceramics slightly decreased as the Zr contents increased. The dielectric constant, piezoelectric constant, and electromechanical coupling factor of samples were maximized at x = 0, which might be due to the increase in density. A high d 33 = 194 pC/N, k p = 38% were obtained for the 0.98NKN–0.02BZT ceramics sintered at 1090 °C for 4 h.