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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]

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]

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]

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]

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]

• 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]