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Magnetoelectric (ME) composite thin films are promising candidates for novel applications in future nanoelectronics, spintronics, memory, and other multifunctional devices as they exhibit much higher ME coupling and transition temperatures (Tc) than well-known single phase multiferroics discovered to date. Among the three types of multiferroic composite nanostructures, (2–2) layered and (1–3) vertically aligned composite nanostructures exhibit comparatively smaller ME coupling due to different shortcomings that restrict their use in many applications. Here, we study the morphological, piezoresponse force microscopic (PFM), ferroelectric, magnetic, and magnetodielectric properties of 0–3 [magnetic nanoparticles (0) homogeneously distributed in ferroelectric matrices (3)] multiferroic composite thin films. The Pb(Fe0.5Nb0.5)O3 (PFN)–Ni0.65Zn0.35Fe2O4 (NZFO) particulate composite films were synthesized by pulsed laser deposition. These particulate composite thin films are completely c-axis oriented with very low surface roughness. We observed magnetic and ferroelectric Tc above room temperature (RT) for all composite thin films. The PFN–NZFO 0–3 composites exhibit large polarization, high saturated magnetization with low coercive field, and low dielectric loss along with magnetodielectric coupling at RT. These nanocomposites might be utilized in next generation nano/microelectronics and spintronic devices. [ABSTRACT FROM AUTHOR]

Vanadium oxide (VO2) thin films have drawn significant research and development interest in recent years because of their intriguing physical origin and wide range of functionalities useful for many potential applications, including infrared imaging, smart windows, and energy and information technologies. However, the growth of highly epitaxial films of VO2, with a sharp and distinct controllable transition, has remained a challenge. Here, we report the structural and electronic properties of high quality and reproducible epitaxial thin films of VO2, grown on c-axis oriented sapphire substrates using pulsed laser deposition at different deposition pressures and temperatures, followed by various annealing schedules. Our results demonstrate that the annealing of epitaxial VO2 films significantly enhances the Semiconductor to Metal Transition (SMT) to that of bulk VO2 transition. The effect of oxygen partial pressure during the growth of VO2 films creates a significant modulation of the SMT from around room temperature to as high as the theoretical value of 68 °C. We obtained a bulk order transition ≥104 while reducing the transition temperature close to 60 °C, which is comparatively less than the theoretical value of 68 °C, demonstrating a clear and drastic improvement in the SMT switching characteristics. The results reported here will open the door to fundamental studies of VO2, along with tuning of the transition temperatures for potential applications for multifunctional devices. [ABSTRACT FROM AUTHOR]

With the rapid development of new device miniaturization technology, there is invigorated interest in magnetic nanostructures for potential application in novel multifunctional devices. In continuation to our search for a suitable magnetic material having Curie temperature (Tc) well above room temperature for multifunctional applications, we have studied the dielectric, optical, magnetic, and resistance switching characteristics of Ni0.65Zn0.35Fe2O4 (NZFO) thin films. The observation of only (004) reflection in the X-ray diffraction patterns confirms the c-axis orientation and high quality growth of NZFO thin films. The presence of mixed valences of Fe2+/Fe3+ cations is probed by X-ray photon spectroscopy, which supports the cationic ordering-mediated large dielectric response. Our investigations reveal NZFO to be an indirect band gap material (~1.8eV) with a direct gap at ~2.55eV. These nanostructures exhibit high saturation magnetization and a low coercive field with a ferrimagnetic-paramagnetic phase transition of ~713K. Magnetic force microscopy studies revealed the stripe-like domain structure of the investigated thin films. In addition, these thin films exhibit reliable and repeatable unipolar resistive switching characteristics. The observed high dielectric permittivity with low loss tangent, large magnetization with soft magnetic behavior, striped magnetic domain structure and reliable resistance switching in NZFO thin films above room temperature suggest potential application in memory, spintronics, and multifunctional devices. [ABSTRACT FROM AUTHOR]

Thin films of vanadium dioxide (VO2) are deposited on indium tin oxide (ITO), stainless steel (SS), and glass substrates using chemical vapour deposition. X-ray diffraction and Raman spectroscopy measurements confirmed the single phase nature of the VO2, which showed a phase transition from a low conducting state at low temperature(<68 °C) to a high conducting state at high temperature (>68 °C). This was confirmed by electrical conductance and infra-red reflectance measurements. X-ray photoelectron spectroscopy was used to measure the charge states of vanadium species. The optical constants of VO2 were determined using visible and near-infra red(NIR) reflectivity and show that the VO2 film on ITO has a lowered plasma frequency compared with VO2 on glass substrates. The thin films of VO2 enable a broadband of ultra-high absorption at mid-wave infra-red frequencies due to a Fabry-Pérot (F-P) like resonance due to the dielectric properties of ITO, SS, or glass. The tunability of this absorption band via VO2 thickness and the switchability by temperature makes the system attractive for absorptive coatings with controllable emissivity. [ABSTRACT FROM AUTHOR]

Abstract Varying the substrate temperature changes structural and magnetic properties of spinel ferrite Ni 0.65 Zn 0.35 Fe 2 O 4 (NZFO) thin films. X-ray diffraction of films grown at different temperature display only (004) reflections, without any secondary peaks, showing growth orientation along the c-axis. We find an increase in crystalline quality of these thin films with the rise of substrate temperature. The surface topography of thin films grown at different growth temperatures reveal that these films are smooth with low roughness; however, the thin films grown at 800 °C exhibit lowest average and root mean square (rms) roughness among all thin films. We find iron and nickel to be more oxidized (greater Fe3+ and Ni3+ content) in films grown and annealed at 700 °C and 800 °C, compared to those films grown at lower temperatures. The magnetic moment is observed to increase with an increase of substrate temperature and all thin films possess high saturation magnetization and low coercive field at room temperature. Films grown at 800 °C exhibit a ferrimagnetic–paramagnetic phase transition well above room temperature. The observed large magnetizations with soft magnetic behavior in NZFO thin films above room temperature suggest potential applications in memory, spintronics, and multifunctional devices. Highlights • Highly c-axis oriented NZFO thin films were grown by PLD technique. • Varying the substrate temperature changes structural and magnetic properties. • All thin films exhibit high Ms, low Mr and low Hc at room temperature. • The M s is found to be increased with increase of substrate temperature. • Thin films grown at 800 °C exhibit a ferrimagnetic Tc ∼716 (±10) K. [ABSTRACT FROM AUTHOR]

Doping of nonmagnetic impurities in technologically important ZnO has opened a new window for achieving room temperature ferromagnetism, p -type carrier conduction, and enhancement of ferroelectric properties. Here, we report on the confined optical phonon and bandgap engineering in highly oriented Li implanted ZnO thin films. Using resonance Raman scattering condition, the confined longitudinal optical phonon lineshapes in uniaxial hexagonal wurtzite crystal are analyzed in detail using the phonon confinement model. We have demonstrated that phonon confinement model can yield a meaningful result for the interpretation of resonance Raman lineshapes if one considers the contribution of both the E 1 (LO) and A 1 (LO) modes, particularly while dealing with oriented ZnO thin films. Furthermore, with the increase in Li dose, the bandgap of ZnO is found to show a blue shift, and such blue shift in bandgap is explained using first principles calculation. • Pulsed laser deposited highly oriented ZnO thin films are implanted with low energy Li ions of different dose. • With the increase in Li concentration, the bandgap of ZnO is found to show a blue shift. • The blue shifting of the bandgap is explained using first principles calculation. • The phenomenological Phonon confinement model is used to explain the line shape of the Raman spectra under resonant conditions. [ABSTRACT FROM AUTHOR]

La0.60Sr0.40MnO3 (LSMO) thin films of varying thickness from 12 to 55 nm were deposited using the pulsed-laser deposition technique onto single-crystalline SrTiO3 (STO) and STO-buffered Si substrates. The Tc of LSMO films grown on STO-buffered Si substrates decreases faster than films directly grown on STO with decreasing film thickness. The LSMO/STO film with thickness of 55 nm shows Tc at about 360 K, which is close to the bulk value, whereas Tc LSMO film on STO-buffered Si film of similar thickness is reduced to 320 K. This difference is attributed to the strain and interfacial disorders in LSMO film on STO/Si. The film surface morphology is influenced by the film thickness. Oxygenation of LSMO films on STO-buffered Si affects the Tc minimally but improved the overall magnetization of the films due to better oxygenation, which is also the case for postannealing the sample at elevated temperatures. The thermomagnetic history effects observed in LSMO films of STO-buffered Si indicate the presence of inhomogeneity, mostly at the interface, which influences the magnetic properties significantly. [ABSTRACT FROM AUTHOR]

Magnetoelectric multiferroic Properties of BTO/CFO/BTO thin films grown on Pt/TiO 2 /SiO 2 /Si. [Display omitted] • Multiferroic thin films were successfully grown using PLD. • Improved magnetoelectric properties for BTO-CFO-BTO. • Interesting multiferroic and magnetoelectric properties. A magnetoelectric multiferroic bi-phase system with robust ferroelectric and ferro/ferri-magnetism response at room temperature would be ideally suitable for microelectronics, memory devices, and for spintronic applications. BaTiO 3 /CoFe 2 O 4 /BaTiO 3 (BTO/CFO/BTO) heterostructured films were pulsed laser deposition grown on Pt(1 1 1)/TiO 2 /SiO 2 /Si substrates. High quality polycrystalline films were grown by thermal annealing at 750 °C, at an oxygen partial pressure of 100 mTorr for 1 h. Crystal quality and phase formation information was monitored using X-ray diffraction (XRD). XRD confirm the growth of polycrystalline heterostructures and the coexistence of both perovskite BTO and spinel CFO phases in heterostructures. In order to obtain robust magnetoelectric coupling, we studied the tri-layer structure as a representative ferroelectric/ferrimagnetic/ferroelectric system. We report the ferroelectric, leakage current behavior, ferrimagnetic, and frequency dependent ME properties of the films. Ferroelectric BTO and ferrimagnetic inverse spinel CFO nature is also confirmed using the piezoresponse force microscopy and magnetic force microscopy measurements. These nanostructures exhibit high saturation polarization (Ps ∼ 99.86 µC/cm2), saturation magnetization (Ms ∼ 51.48 emu/cm3), and a strong ME coupling coefficient of ∼ 274 mV/cm-Oe with a bias magnetic field of + 90 Oe, anda frequency of 1 kHz revealing them as prospective candidates for multifunctional applications. [ABSTRACT FROM AUTHOR]

We report the electrothermal properties of AAA trilayer on polyethylene terephthalate substrate which allowed the development of low-cost high-performance transparent thin-film flexible heater (TTFFH) using RF magnetron sputtering. The structural, electrical, and optical properties of the AAA trilayer were investigated at different thickness of the Ag interlayer. The AAA trilayer-based TTFFH yielded saturation temperatures beyond 100 °C at 10 V at optimized Ag interlayer thickness of 5 nm. The time-dependent temperature profile along with its highly stable and reversible thermal behavior was studied. Most importantly, the AAA trilayer-based TTFFH provides a high-performance alternative to the conventional and expensive ITO electrodes at a much lower cost. [ABSTRACT FROM AUTHOR]

Abstract: The growth of TiO2 nanorods by a simple sputtering method is reported. Here we show that by sputtering of Ti target in argon–oxygen plasma it is possible to grow rutile core and anatase shell heterostructure TiO2 nanorods on gold (Au) coated Si(100) substrate without external heating. It seems that the nanorods grow because of the stress assisted diffusion of under-laying Au atoms into the TiO2 film followed by catalytic growth of the nanorods at the root. [Copyright &y& Elsevier]

A new plasticized composite polymer electrolyte (PCPE) based on poly(ethylene oxide)–NaClO4 dispersed with a ceramic filler (SnO2) and plasticized with polyethylene glycol (PEG200) is reported. The effect of plasticizer concentration on changes in structure/microstructure and their correlation with physical properties has been investigated and reported. A substantial enhancement in the electrical conductivity, by two orders of magnitude at room temperature, of the PCPE has been noticed when compared with that of composite polymer electrolyte (CPE) films without any plasticizer. This enhancement in electrical conductivity of the PCPE films agrees well with the changes in the local microstructure/structure on plasticizer addition. Grain boundary resistance (Rgb) and glass transition temperature (Tg) have been observed to decrease with increasing concentration of PEG200. Plasticizer addition has resulted in the suppression of crystallinity as observed from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. The DSC results indicate enhancement in the volume fraction of the amorphous phase, which appears to be consistent with the broadening in the polymer host peaks observed in X-ray diffractograms. The improvement in electrical conductivity has been achieved without any sharp deterioration in the thermal, electrochemical or mechanical stability of the PCPE thin films. These observations have been interpreted in terms of the action of plasticizer as a diluent/co-solvent. [Copyright &y& Elsevier]

We report on the observation of remarkable room-temperature ferromagnetism in nanocrystalline epitaxial Co:TiO2 films grown on sapphire (0001) substrates by a pulsed-laser deposition technique using high-density targets. The films were characterized by x-ray measurements, atomic force microscopy, micro-Raman, electron-paramagnetic resonance, and magnetization studies. The films exhibit three-dimensional islandlike growth that contains nanocrystalline particles. Our experimental results suggest that the remarkable ferromagnetism in Co:TiO2 films is controlled either by the interstitial Co2+ ions or small clusters, which are mainly present at the interface and on the surface of the films. Our work clearly indicates that Co interstitials and nanoclusters cause room-temperature ferromagnetism in Co-doped TiO2. [ABSTRACT FROM AUTHOR]

We report on the observation of remarkable room-temperature ferromagnetism in epitaxial (Zn,Mn)O films grown by a pulsed-laser deposition technique using high-density targets. The optimum growth conditions were demonstrated from x-ray measurements, microstructure, Rutherford backscattering, micro-Raman, and magnetic studies. Superior ferromagnetic properties were observed in (Zn,Mn)O films grown at a substrate temperature of 500 °C and with an oxygen partial pressure of 1 mTorr. Ferromagnetism becomes weaker with increasing substrate temperature due to the formation of isolated Mn clusters irrespective of higher crystalline quality of the film. [ABSTRACT FROM AUTHOR]

Growth of Al2O3 films on Si(1 1 1) substrates by metalorganic chemical vapor deposition (MOCVD) has been investigated. Films were deposited by MOCVD with aluminum–acetylacetonate as a precursor at various temperatures. At low temperatures (350–550 °C) amorphous films were obtained. As the temperature increased beyond 550 °C, the presence of crystalline Al2O3 was detected. At high temperatures (750–950 °C), the crystallinity of the film increased and a 〈0 1 1〉 κ-Al2O3 textured film growth was observed at 950 °C. [Copyright &y& Elsevier]

We report transport, magnetization, and transmission-electron-microscopic studies of La[sub 1-x]Ba[sub x]MnO[sub 3]/SrTiO[sub 3] thin films grown by pulsed-laser deposition. The metal–insulator transition is remarkably sharp, and the high value of the temperature coefficient of resistivity is significantly relevant for the required value for the infrared imaging applications. We have demonstrated that the strain-induced property can be tuned and stabilized in La[sub 1-x]Ba[sub x]MnO[sub 3] films simply by changing the doping level (La/Ba ratio) and addition of metal ions (Ag) for applications at desirable temperature regime close to room temperature. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Artificial and engineered nanostructures expand the degrees of freedom with which one can manipulate the intricate interplay of light and matter. Certain nanostructural arrangements in the excited state enable the efficient electromagnetic coupling of propagating light with localized fields. Here, we demonstrate that light transmitted through a nanostructured metal thin film without any apertures can be significantly enhanced. Distinct asymmetric Fano resonances are observed in the zero-order transmission spectra using an incoherent light source. The transmission efficiency surpasses that of a metal thin film with the same area and thickness at the resonance maxima. The transmission minima and the sharp resonance maxima bear a strong resemblance to the extraordinary optical transmission observed in sub-wavelength nanohole array structures The resonance wavelength closely matches the nanostructural periodicity. The sensitivity of the resonances to the surrounding medium and the transmission efficiency demonstrate the potential for use in energy harvesting, imaging, optical processing and sensing applications. [ABSTRACT FROM AUTHOR]

With a metal to insulator transition (MIT) temperature of ∼68 °C to 70 °C, which is close to room temperature (RT), vanadium oxide (VO2) has piqued interest in research communities for several applications, such as Mott-transistors and smart windows. This unique characteristic and multi-faceted application of VO2 makes it ideal for several fields, from consumer electronics to defense applications. However, despite this advantage over several other materials, VO2 has some serious shortcomings. In this paper, we attempt to address these issues, such as higher than RT transition temperature, metastability of the material, and its need for a separate heater layer to trigger the MIT, by using a stoichiometrically downgraded multi-layered structure that can both demonstrate the MIT property and serve as an embedded heater layer. This eliminates the need to use a system with a different material such as aluminum-doped zinc oxide. By using the multi-layered structure, we were able to achieve a transition temperature of ∼48 °C, which is ∼22 °C lower than the transition temperature of bulk VO2 films. We also noted a reduction of over 50% in transmission in the infra-red region by application of less than 15 V, as well as an enhancement of ∼10% in the visible region transmission beyond the MIT temperature, which demonstrates the potential of this structure to be used as an energy-efficient smart window device. [ABSTRACT FROM AUTHOR]

The metal-to-insulator transition (MIT) closest to room temperature of 68–70 °C as shown by vanadium oxide (VO2), compared with other transition metal oxides, makes it a potential candidate for smart window coating. We have successfully fabricated a potential smart window device after the optimum design of a multilayered thin film structure made out of transparent conducting oxide (aluminum doped zinc oxide) and pure VO2 using pulsed laser deposition technique. This comprehensive study is based on two different configurations for multi-layered structure approach, with the intention to reduce the transition temperature, as well as to maintain the MIT properties that would strengthen the potential of the structure to be used for a smart window device. By creating a multi-layered structure, we were able to create a low powered device that can operate less than 15 V that leads to significant decline in the infrared transmission by a magnitude of over 40% and provided sufficient heat to trigger the MIT at a temperature around 60 °C, which is almost 10 °C lower than its bulk counterpart. This finding would positively impact the research on VO2 thin films, not only as smart windows but also for numerous other applications like bolometers, infrared detectors, Mott transistors and many more. [ABSTRACT FROM AUTHOR]

We report on high performance transparent Al:ZnO (AZO) thin film heaters on flexible polymer (polyethylene terephthalate) and glass substrates which demonstrate low sheet resistivity. AZO thin films were grown by radio-frequency magnetron sputtering at low Ts (below 200°C) on flexible, transparent polyethylene terephthalate substrates that show stable and reproducible results by applying low (<10 V) voltages. This study also examined identical AZO thin films on glass substrates that showed highly reproducible heating effects due to the Joule heating effect. The potential applications are foldable and wearable electronics, pain/injury therapy smart windows, automobile window defrosters, and low-cost power electronics. [ABSTRACT FROM AUTHOR]

We report on the study of high quality Pb(Zr,Ti)O3 thin films grown by radio-frequency magnetron sputtering on (0 0 0 1) ZnO with an MgO interfacial seed layer. A systematic investigation of the heterostructures has been performed by x-ray diffraction, atomic force microscopy (AFM) and ultraviolet–visible spectroscopy for the structural and optical properties, along with the electrical characterization and simulation. (0 1 1)-oriented perovskite phase was observed in Pb(Zr,Ti)O3 thin films which used the MgO seed layer, whereas the pyrochlore phase was dominant in the films deposited directly on ZnO. The surface morphology measured by AFM indicated that the introduction of the MgO interfacial seed layer promoted formation of a smooth surface and uniform grain structures in the thin films. The transmission spectra also showed an increase of the optical transmittance measured by ultraviolet–visible spectroscopy. The capacitance–voltage measurements exhibited butterfly-shaped capacitance curves which bear a resemblance to those of the typical metal–ferroelectric–metal structures. The characteristics of the polarization versus electric field were investigated by a simulation to understand the behaviour of the hysteresis loops in this metal–ferroelectric–insulator–semiconductor structure. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline zinc films were deposited on gold coated borosilicate glass substrates by thermal evaporation method using zinc powders as the source material and then treated with argon plasma at various temperatures. From X-ray diffraction study, the as-deposited films are found to be metallic Zn and polycrystalline in nature. The crystalline nature improves with the increase of temperature up to 200°C and decreases with the further increase of temperature to 300°C. The binding energy observed for Zn 2p3/2, and the binding energy separation between Zn 2p3/2 and Zn 2p1/2 in the X-ray photoelectron spectrum indicate that the films are metallic zinc films. Transmission electron microscopic study shows hexagonal shaped grains having size ∼58nm upon treatment with Ar plasma. It is clearly shown the grain growth and distinct grain boundary with the increase in temperature. The average Young''s modulus (E) and hardness (H) are measured to be 84GPa and 4.0GPa for as-deposited film, whereas 98GPa and 5.8GPa for plasma treated film at 200°C. The enhancement in mechanical properties is attributed to improvement in crystalline nature of the film and better interlinking between grains and boundaries. [Copyright &y& Elsevier]

Combining two materials in a nanoscale level can create a composite with new functionalities and improvements in their physical and chemical properties. Here we present a high-throughput approach to produce a nanocomposite consisting of metal nanoparticles and semiconductor oxide nanostructures. Volmer-Weber growth, though unfavorable for thin films, promotes nucleation of dense and isolated metal nanoparticles on crystalline oxide nanostructures, resulting in new material properties. We demonstrate such a growth of Au nanoparticles on SnO2 nanostructures and a remarkable sensitivity of the nanocomposite for detecting traces of analytes in surface enhanced Raman spectroscopy. Au nanoparticles with tunable size enable us to modify surface wettability and convert hydrophilic oxide surfaces into super-hydrophobic with contact angles over 150°. We also find that charge injection through electron beam exposure shows the same effect as photo-induced charge separation, providing an extra Raman enhancement up to an order of magnitude. [ABSTRACT FROM AUTHOR]

Large area highly crystalline MoS2 and WS2 thin films were successfully grown on different substrates using radio-frequency magnetron sputtering technique. Structural, morphological and thermoelectric transport properties of MoS2, and WS2 thin films have been investigated systematically to fabricate high-efficient thermal energy harvesting devices. X-ray diffraction data revealed that crystallites of MoS2 and WS2 films are highly oriented in 002 plane with uniform grain size distribution confirmed through atomic force microscopy study. Surface roughness increases with substrate temperature and it plays a big role in electron and phonon scattering. Interestingly, MoS2 films also display low thermal conductivity at room temperature and strongly favors achievement of higher thermoelectric figure of merit value of up to 1.98. Raman spectroscopy data shows two distinct MoS2 vibrational modes at 380 cm−1 for E12g and 410 cm−1 for A1g. Thermoelectric transport studies further demonstrated that MoS2 films show p-type thermoelectric characteristics, while WS2 is an n-type material. We demonstrated high efficient pn-junction thermoelectric generator device for waste heat recovery and cooling applications. [ABSTRACT FROM AUTHOR]

We have demonstrated the fabrication of highly continuous and smooth CdSe semiconductor films containing self-assembled nanocrystals (NCs) using a simple, low cost solution-processed deposition technique. The impact of thermal annealing and ethanedithiol (EDT) treatment on oleate capped CdSe NCs films is illustrated. Post deposition EDT treatment enhances strong electron coupling between NCs by reducing the inter-particle distance, which enhances four orders of magnitude of photocurrent in the pn-device. Mild thermal annealing of NC films cause large redshift and significant broadening. Our findings suggest that NCs with short-range organic ligands are suitable for high-performance Thin-Film-Transistors and next generation high-efficiency photovoltaics. [ABSTRACT FROM AUTHOR]

We demonstrate the growth temperature dependence of film thickness and surface roughness of ZnO films grown by atomic layer deposition using ozone as an oxidizer. The significantly low growth rate of the film using O3 precursor is attributed to the recombinative surface loss of O3. The variation of the spatial uniformity inferred from the surface roughness of the ZnO films and the O3 concentration was explained by a transition from reaction- to recombination-limited growth. We have fabricated a metal–oxide–semiconductor device, consisting of an insulating ZnO layer using an O3 source, between metallic and semiconducting Al : ZnO layers. The device demonstrates a remarkable resistive switching behaviour. The electrochemical migration of oxygen vacancies, which is created in the vicinity of the interface of ZnO semiconductor–ZnO insulator, drives the resistive switching behaviour. This significant result produced on the all-oxide-based device fabricated by atomic layer deposited ZnO can have significant impact for multifunctional applications. [ABSTRACT FROM AUTHOR]

• Combinatorial thin film synthesis of bimetallic Ag x Fe 1−x alloy for rapid materials characterization. • Correlation of composition and structure to the optical and magnetic properties of Ag x Fe 1-x thin films. • Magnetic measurements reveal Ag x Fe 1−x has an antiferromagnetic phase Néel temperature of ≈120 K. • Controlled phase separation in immiscible Ag-Fe system results in tunable magneto-optical properties. Bimetallic alloys with large discrepancies in atomic radii and crystal structure typically yield systems that are highly immiscible, even at high temperatures. The Ag x Fe 1−x binary system has limited solid and liquid solubility and thus phase separated Ag + Fe alloys should result. Furthermore, Ag has interesting plasmonic properties and Fe is a strong ferromagnet, thus magneto-plasmonic nanoparticles/films should result due to their phase separation. We have leveraged a combinatorial sputter deposition to synthesize thin films with a large Ag x Fe 1−x (0.19 < x < 0.84) phase space to correlate the composition and structure to the optical and magnetic properties for both as-deposited and annealed compositions. [ABSTRACT FROM AUTHOR]

• Temperature dependent dielectric studies on SrTiO 3 /SrRuO 3 /GaFeO 3 (STO/SRO/GFO) suggest the ferroelectric-relaxor behavior. • Magnetization vs Temperature measured both at field-cooled (FC) and (zero-field-cooled) ZFC shows large bifurcation with transition temperature at 240 K. • The clear and reversible out-of-phase contrast is seen in the piezoresponse force microscopy (PFM) phase and amplitude images. • Polarization vs electric field (P-E) hysteresis loop study on STO/SRO/GFO/Pt reveals the remanent polarization of polarization of ∼30 µC/cm2 and coercive field (E C) of 0.09 MV/cm. We report a detailed investigation on magnetic and electrical properties of the multiferroic GaFeO 3 (GFO) thin films grown on SrRuO 3 (SRO) buffered SrTiO 3 (1 1 1) substrates. The magnetic transition temperature (T c) of GFO thin films is observed ∼240 K, which is higher by 20 K than in GFO ceramic. The clear and reversible out-of-plane phase-contrast seen in the Piezoresponse Force Microscopy (PFM) phase and amplitude images measured within positive and negative poling confirms the polarization reorientation and hence piezoelectric nature of the compound. The temperature and frequency dependence of permittivity studies demonstrates the relaxor behavior of these thin films. The observed near room temperature (RT) magnetic phase transition with RT piezoelectric nature of these thin films elucidates the possible potential candidates for a multiferroic world with spintronics device applications. [ABSTRACT FROM AUTHOR]

We report the synthesis of epitaxial As-doped ZnO and Mn-doped (ZnAs)O films by pulsed-laser deposition technique. The grain size in (ZnAs)O films decreases from 40 to less than 10 nm upon Mn doping, illustrating that Mn acts as a potential catalyst to create nanosize grains. Temperature dependent electrical resistance shows metal-insulator transition and metal-semiconductor transition (MST) at 165 and 115 K, respectively, in (ZnAs)O, although Mn doping suppresses MST completely. Both ionization efficiency on oxygen vacancies and percolation of charge carriers may be responsible for such transitions. In addition, electrical conduction in these films shows strong aging effects. [ABSTRACT FROM AUTHOR]