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In order to acquire a soft magnetic film with low conductivity and large magnetic anisotropy, the strain-modulated magnetic anisotropy is studied in epitaxial MgFe2O4 (MFO) films. The MFO films with thicknesses of 25, 48, 75, and 110 nm are grown on the MgAl2O4 (MAO) (100) substrate using a pulsed laser deposition technique. Due to the large lattice-mismatch (3.34%) between MFO and MAO substrates, the interface exhibits a large tetragonal compressive strain. The results of field-dependent magnetization suggest the soft magnetic nature of all the measured MFO films. The analysis of angular dependent ferromagnetic resonance reveals the large uniaxial magnetic anisotropy energy (Ku) of −1.62 × 106 erg/cm3 in the highly strained 25 nm film, and Ku decreases with the increasing thickness due to strain relaxation. The observed large magnetic anisotropy in these highly strained MFO thin films is larger than most of the soft ferrite thin films, which arise due to tetragonal distortion and inverse magnetostriction. The epitaxial MFO thin films with enhanced magnetic anisotropy could be one of the potential candidates for spin filters. [ABSTRACT FROM AUTHOR]

Laser surface micro-treatment refers to the use of appropriate laser energy to induce the surrounding gas and stainless steel reaction to produce a film or the use of large laser energy to manufacture micrometer grating. Using the principle of thin film interference or grating diffraction, the surface of stainless steel is marked with color, which can be used for information storage of metallurgical products. The relationship between laser line scanning and laser power is studied experimentally, the range of laser power density with color variation is obtained, and the optimal process parameters of uniform color are obtained. [ABSTRACT FROM AUTHOR]

The Ag sulfurization resistance of the pure Ag film and four Ag-based alloy films was evaluated by the reflectance decay after the Ag sulfurization test. Among all Ag-based alloy films, the In alloying solute in the Ag-In alloy film shows the best resistance to the Ag sulfurization. Using x-ray photoelectron spectroscopy analysis, the chemical state of the alloying solutes in the Ag-based alloy films was examined. It is found that, with being alloyed in the Ag matrix phase, the 3d5/2 core-level peak positions of the alloying solutes (In, Sn, and Pd) shift toward the lower binding energy region, which is defined as a negative chemical shift. The chemical shifts of In, Sn, and Pd alloying solutes are –0.31 eV, –0.23 eV, and –0.2 eV, respectively. The absolute value of the negative chemical shift represents the tendency of Ag atoms losing valence electrons to the alloying solutes. As the Ag atoms lose valence electrons to the alloying solutes, the Ag atoms have a less tendency to provide the valence electrons to form covalent bonding with S atoms, which suppresses the Ag sulfurization reaction (2Ag + S → Ag2S). Therefore, the larger the absolute value of the negative chemical shift, the higher is the reflectance decay (lesser Ag sulfurization resistance). [ABSTRACT FROM AUTHOR]

The effects of oxygen concentration and film thickness were studied on the microstructural, electrical, and magnetic properties of Fe65Co35–O alloy films prepared by dc magnetron sputtering at room temperature. The films showed the best magnetic softness with a large saturation magnetization of 21.5 kG, low coercivities of 2.8 and 2.1 Oe in easy and hard axes, respectively, and a high resistivity of 2215 μΩ cm at an optimized condition of an oxygen gas flow ratio of 1.0% and a film thickness of 105 nm. Such an excellent magnetic softness can be attributed to grain refinement caused by the addition of very low dose of oxygen, which basically did not lead to the full formation of Fe and/or Co oxide phases with low saturation magnetizations. The microwave permeability measurement indicated that the addition of very low dose of oxygen could improve the response of real permeability to frequency. A high real permeability of 525 at frequency up to 1.2 GHz was obtained for the Fe65Co35–O films deposited at the optimized condition above. [ABSTRACT FROM AUTHOR]

Structural and resistive anisotropy has been studied for the Bi0.4Ca0.6MnO3 films grown on (011)-oriented SrTiO3 substrates. Strong anisotropic transport behaviors are observed when significant lattice strains exist. The ratio of the two resistivities along the a and c axes of the films can be tuned between ∼1 and ∼13 by adjusting the a/c ratio between ∼1.01 and ∼1.04, which can be conducted simply by decreasing film thickness from 100 to 10 nm. Considerable anisotropy emerges and develops when film thickness drops below ∼60 nm. With the decrease in film thickness, a change in preferred growth direction of the films is also observed. These features of the lattice effects could be useful for the design of artificial materials and devices. [ABSTRACT FROM AUTHOR]

Magneto-optical Kerr effect, low-energy electron diffraction, and Auger electron spectroscopy were used to investigate the magnetic properties and the growth mode of ultrathin Co films deposited on 1 ML (monolayer) Ni/Pt(111) at room temperature. No Kerr signal was observed when the thickness of Co film was below 3 ML, and the easy axis of the magnetization was in plane when the thickness of Co was greater than 3 ML at room temperature. The polar Kerr signal appeared after the sample was annealed at 450 K for 1 ML of Co. Further studies in the magnetic properties and surface composition of 3 ML Co/1 ML Ni/Pt(111) during an annealing process showed that the out-of-plane magnetization enhances significantly when Co and Ni atoms diffuse into the Pt substrate. The coercivity of the system can be adjusted by changing the annealing temperature. Measuring at room temperature, the coercivity increases when the annealing temperature rises. The possible mechanism of the evolution of magnetic properties with the structure of the interface is discussed. [ABSTRACT FROM AUTHOR]

Self-assembled zinc oxide (ZnO) and indium-doping zinc oxide (ZnO:In) nanorod thin films were synthesized on quartz substrates without catalyst in aqueous solution by sol-gel method. The samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), Raman-scattering spectroscopy, room-temperature photoluminescence (PL) spectra, and temperature-dependent PL spectra measurements. XRD and Raman spectra illustrated that there were no single In2O3 phase in ZnO lattice after indium doping. The PL spectra of ZnO showed a strong UV emission band located at 394 nm and a very weak visible emission associated with deep-level defects. Indium incorporation induced the shift of optical band gap, quenching of the near-band-edge photoluminescence and enhanced LO mode multiphonon resonant Raman scattering in ZnO crystals at different temperatures. Abnormal temperature dependence of UV emission integrated intensity of ZnO and ZnO:In samples is observed. The local state emission peak of ZnO:In samples at 3.37 eV is observed in low-temperature PL spectra. The near-band-edge emission peak at room temperature was a mixture of excitons and impurity-related transitions for both of two samples. [ABSTRACT FROM AUTHOR]

Polymer-based thin film transistors (PTFTs) were fabricated on glass substrates with anodized Al2O3 as gate insulators. RR-P3HT (regioregular poly–3-hexylthiophene) and MEH-PPV [poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene)] were respectively used as semiconducting active layers for the transistors. A two orders of magnitude increase in field effect mobility (from 7.2×10-4 cm2/V s to 7.4×10-2 cm2/V s) deduced from electrical data of transistors fabricated using FeCl3 doped RR-P3HT was observed. This increase is believed to be mainly due to a large reduction in contact resistance (from 108 Ω to 103 Ω) to the source and drain Au contacts. The conductivity of RR-P3HT was found to increase only slightly with the doping. For MEH-PPV, doping with FeCl3 also decreased its contact resistance. However, it (4 GΩ) was still much larger than the channel (polymer) resistance (1 MΩ), leading to a slight improvement in its field effect mobility. Theoretically, contacts between Au and P3HT should have very small energy barrier heights (<0.2 eV) for hole injection. We believe that a negative vacuum level shift introduced by metal to organic interfacial dipoles might be the origin of this large energy barrier, as well as to large contact resistance. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

c-axis epitaxial thin films of Bi-layered homologous Sr[sub m - 3]Bi[sub 4]Ti[sub m]O[sub 3m+3] (m = 3, 4, 5, and 6) were fabricated on (001) SrTiO[sub 3] single crystal substrates by pulsed laser deposition, respectively. Microstructures of the films were systematically characterized by x-ray diffraction (including θ-2θ scans, rocking curve scans and φ scans), atomic force microscopy, and transmission electron microscope. Epitaxial relations were established to be (001) Sr[sub m - 3]Bi[sub 4]Ti[sub m] O[sub 3m + 3](001) SrTiO[sub 3] and [1&1macr;0]Sr[sub m - 3]Bi[sub 4]Ti[sub m]O[sub 3m+3][010]SrTiO[sub 3] by φ scans and selected area diffraction. A special kind of atomic shift along the [001] direction and a slight atomic vibration of TiO[sub 6] octahedra were revealed and discussed. The room-temperature dielectric constants of these epitaxial films measured by using an evanescent microwave probe were 245±23, 237±13, 272±19, and 221±20 for films with m = 3, 4, 5, and 6 respectively. [ABSTRACT FROM AUTHOR]

Investigates the stability of C54 titanium germanosilicide on a silicon-germanium alloy substrate. Information on the formation of the films from a solid phase metallization reaction; Examination of the structural properties of the alloys using a Rigaku x-ray diffractometer; Details on the surface and interface morphologies.

Presents a study which determined the lattice constant, strain relaxation, thickness and critical thickness of a thin In[subx]Ga[sub1-x]As heterostructure embedded in GaAs using x-ray rocking curve technique. Experimental details; Results and discussion; Conclusions.

Presents a study that examined the resistive properties of superconducting yttrium-baron-copper-oxygen (YBaCuO) thin films. Measurement of the resistivity versus temperature and resistivity versus current density properties of the films; Temperature dependence of electrical resistance of superconducting YBaCuO thin film.

The substrate induced anisotropic strain was found to have a significant effect on the charge ordering (CO) transition and surface morphology in Bi0.4Ca0.6MnO3 films deposited on (110)- and (111)-oriented SrTiO3 substrates. Effects of film thickness t on the CO transition were further studied. The CO transition appears at TCO when t exceeds 50 nm, and develops rapidly to an excellent state as t reaches 100 nm. The distinctive thickness-dependent CO transition has a close relation with the anisotropic strain relaxation process. [ABSTRACT FROM AUTHOR]

Fe3O4 thin films with a thickness of about 140 nm have been deposited on MgO (001) substrates by reactive sputtering. Microstructural studies indicated that monocrystalline Fe3O4 thin films were epitaxially grown on the MgO substrates with a cubic-on-cubic orientation relationship with respect to the substrates. Strain field due to slight lattice mismatch between the films and substrates was observed. The saturation moment and the coercivity for in-plane magnetization hysteresis loop were 235 emu/cc and 500 Oe, respectively. The lower saturation moment value of the Fe3O4 thin film suggested that the strain field may play a role in the reduction of magnetization. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A voltage-induced unidirectional threshold resistive switching has been reported for Au/NiO/Nb:SrTiO3 devices fabricated by pulsed laser deposition. The devices show the threshold resistive switching behavior only for the positive voltages, determined by the forming process. The currentvoltage (I-V) and capacitance-voltage (C-V) characteristics of the as-grown samples with different thicknesses suggest that the I-V and C-V properties are dominated by the Schottky junction at the NiO/Nb:SrTiO3 interface and NiO film, respectively, indicating the formation of conductive filaments in NiO film. Furthermore, the effect of NiO-film thickness on the resistive switching, as well as the I-V and C-V characteristics, indicates that the unidirectional threshold resistive switching originates from the combined contributions of the interfacial Schottky junction modulation and the bipolar threshold switching related to the unstable conductive filament in NiO film. Our research results provide additional insights into the resistive switching mechanism as well as applications of selector device. [ABSTRACT FROM AUTHOR]

Cadmium sulfide thin films with different doping concentration of indium were deposited by magnetron sputtering. The effects of indium concentration on the structure, electrical and optical properties of CdS thin films were studied. XRD results show that all In-doped CdS thin films mainly have face-centered cubic structure with preferred orientation in (111) direction. The optical band gap of CdS:In films varied with indium concentration while the average grain size has an opposite dependency on indium. The carrier concentration increased by 1~3 magnitudes with indium concentration. CdTe solar cells based on CdS:In window layer were fabricated to verify the doping effect of indium on CdS thin films. Photo current density-voltage characteristics and EQE spectra suggest that indium can effectively enhance the collection of carriers in depletion area, which leads to improve both Voc and Jsc. Indium doped CdS layer coupled with standard CdTe preparation process has yielded up to 15.53% efficiency solar cell on commercialized TCO substrates. [ABSTRACT FROM AUTHOR]

Nanocrystalline Ag, Cu, and Ni thin films and their coarse grained counterparts are patterned using focused ion beam and then irradiated by Kr ions within an electron microscope at room temperature. Irradiation induced in-plane strain of the films is measured by tracking the location of nanosized holes. The magnitude of the strain in all specimens is linearly dose-dependent and the strain rates of nanocrystalline metals are significantly greater as compared to that of the coarse grained metals. Real-time microscopic observation suggests that substantial grain boundary migration and grain rotation are responsible for the significant in-plane strain. [ABSTRACT FROM AUTHOR]

Presents a study that investigated the effects of doping on the microstructural and magnetic properties of barium ferrite thin films when chromium oxide or yttrium oxide were used as the dopants. Details of the experiment; Results; Discussion and conclusions.

Al-doped ZnO (AZO) films were deposited by radio frequency (RF) reactive magnetron sputtering. The effects of buffer layer, annealing temperature and atmosphere on the structure, crystallinity and optical properties of epitaxial AZO films were investigated. The XRD results indicate that AZO thin films deposited on buffer layer has a better c -axis preferentially oriented growth than AZO films without buffer layer, and a better crystal quality can be obtained by an appropriate annealing process. The PL spectra show excellent UV/vis light-emitting characteristics: 387 nm, 424 nm, 463 nm and 506 nm. The intensities of the UV/vis peaks change when AZO films are annealed in oxygen or vacuum at different temperatures. The origin of the UV/vis emissions is discussed and the photoluminescence mechanism of AZO films is suggested. [ABSTRACT FROM AUTHOR]

Chemical bath deposition has been used for the growth of Cd xZn1− xS thin films from CdSO4/ZnSO4/CS(NH2)2/NH3·H2O solutions. The deposited films were annealed at 400°C for 30 minutes in an N2 atmosphere. The films were characterised by scanning electron microscope, energy dispersive spectroscopy and UV-visible spectrophotometer. The band gap values of Cd xZn1− xS thin films vary from 2·54 to 3·13 eV as ' x' changes from 0·24 to 0·78. The increased band gap was because of an increase in the concentration of zinc in the deposits. Also, the surface morphology of the material changed according to the concentration of zinc. [ABSTRACT FROM AUTHOR]

Using liquid phase epitaxy (LPE), we developed a new approach to growing a-axis oriented YBa2Cu3O7−δ films (a-films) in air, which have been hard to gain in the prior art since an extremely low supersaturation (σ) is required for their formation. Instead of the conventional step-cooling from a high temperature (Th) above the peritectic temperature (Tp) directly to the growth temperature (Tg), a novel cooling plus heating mode (from Th cooling down to below Tg and then heating back to Tg) was adopted for the film growth. We found that slow cooling combined with fast heating was effective to achieve an extraordinarily low σ for preparing a-films, which are potentially appropriate for Josephson junction devices. Most importantly, the correlation between the cooling mode and the driving force was reviewed, which provided universal guidance for finely tuning supersaturation of the solution. [ABSTRACT FROM AUTHOR]

Porous α-Co(OH) nanoflake array film is prepared by a facile hydrothermal synthesis method. The α-Co(OH) nanoflake array film exhibits a highly porous net-like structure composed of interconnected nanoflakes with a thickness of 15 nm. The pseudo-capacitive behaviour of the Co(OH) nanoflake array film is investigated by cyclic voltammograms (CV) and galvanostatic charge-discharge tests in 2 M KOH. The α-Co(OH) nanoflake array film exhibits high capacitances of 1017 F g at 2 A g and 890 F g at 40 A g as well as rather good cycling stability for supercapacitor application. The porous architecture is responsible for the enhancement of the electrochemical properties because it provides fast ion and electron transfer, large reaction surface area and good strain accommodation. [ABSTRACT FROM AUTHOR]

The heating behavior of La NiO3 ( LNO) films on SiO2/ Si substrate heated by 2.45 GHz microwave irradiation in the microwave magnetic field was first investigated, and then amorphous Pb( Zr0.52 Ti0.48) O3 ( PZT) thin films were deposited on LNO-coated SiO2/ Si substrates by a sol-gel method and crystallized in the microwave magnetic field. The crystalline phases and microstructures as well as the electrical properties of the PZT films were investigated as a function of the elevated temperature generated by microwave irradiation. The perovskite PZT films with a highly (100)-preferred orientation can be obtained by microwave annealing at 700°C for only 180 s of total processing time, and have good electrical properties. The results demonstrated that conductive metal oxide LNO as a bottom electrode layer is an advantage for the crystallization of PZT thin films by microwave irradiation in the microwave magnetic field. [ABSTRACT FROM AUTHOR]

Systematic experiments were performed by in situ observationofthe YBa2Cu3Oz(Y123or YBCO) melting. Remarkably, the superheating phenomenon was identifiedto exist in all commonly used YBCO thin films, that is, films depositedon MgO, LaAlO3(LAO), and SrTiO3(STO) substrates,suggesting a universal superheating mode of the YBCO film. Distinctively,YBCO/LAO films were found to possess the highest level of superheating,over 100 K, mainly attributed to the lattice match effect of LAO substrate,that is, its superior lattice fit with Y123 delaying the Y123 dissolvingand inferior lattice matching with Y2BaCuO5(Y211)delaying the Y211 nucleation. Moreover, strong dependence of the thermalstability on the substrate material for Y123 films was also foundto be associated with the substrate wettability by the liquid andthe potential element doping from the substrate. Most importantly,the understanding of the superheating behavior is widely valid formore film/substrate constructions that have the same nature as theYBCO film/substrate. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline Co45Ni10Fe24 films have been fabricated using cyclic voltammetry technique from the solutions containing sulfate, then characterized by scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Meanwhile, Electrochemical Impedance Spectroscopy technique has been employed to probe into the nucleation/growth behavior of Co45Ni10Fe24 films. The results show that, the obtained Co45Ni10Fe24 film possesses low coercivity of 973.3A/m and high saturation magnetic flux density of 1.59×105 A/m. Under the experimental conditions, the nucleation/growth process of Co45Ni10Fe24 films is mainly under activation control. With the increase of the applied cathodic potential bias, the charge transfer resistance for CoNiFe deposition decreases exponentially. [Copyright &y& Elsevier]

Abstract: Thick GaN films were overgrown by HVPE on nano-island templates, which was fabricated by inductively coupled plasma etching using self-assembled CsCl islands as etch masks. The truncated cone-shape nano-islands exhibited significant effects on improvement of crystalline quality and reduction of crack density for subsequent GaN growth. Photoluminescence and micro-Raman measurements showed improved optical properties and partial strain relaxation in the overgrown GaN when compared to that grown on as-grown template, originated from the initial selective growth. Compared to conventional epitaxial lateral overgrown GaN, the economic and rapid method would put forward new promising pathway to fabricate high quality GaN. [Copyright &y& Elsevier]

Epitaxial growth of CeGdO(CGO) films on (001) TiO-terminated SrTiO substrates by pulsed laser deposition was investigated using in situ reflective high energy electron diffraction. The initial film growth shows a Stransky-Krastanov growth mode. However, this three-dimensional island formation is replaced by a two-dimensional island nucleation during further deposition, which results in atomically smooth CGO films. The obtained high-quality CGO films may be attractive for the electrolyte of solid-oxide fuel cells operating at low temperature. [ABSTRACT FROM AUTHOR]

Abstract: Er-doped ZnO films were deposited by reactive magnetron sputtering technique at different oxygen flow rate. The microstructures, the chemical state of the oxygen and the optical absorption properties of ZnO:Er films were investigated. The X-ray diffraction spectroscopy (XRD) results and the X-ray photoelectron spectroscopy (XPS) analyses about the oxygen in the doped samples indicated that oxygen flow rate has great effect on the crystalline quality of ZnO:Er films. It was concluded that the decrease of the crystalline quality of the samples was caused by the oxygen deficiency. The optical absorption properties and the shift of the optical band gaps were investigated. The analysis reveals that the blue shift of the band gaps was caused due to the decreasing of O2−ions at the intrinsic sites and the increasing of O2-ions at the oxygen deficient regions. [Copyright &y& Elsevier]

Abstract: Photosensitive Ti1−x Co x O2 gel films are prepared by chemical modification with benzoylacetone, and then their Fourier transform infrared spectra and ultraviolet visible spectra are measured. Results show that the chelate rings of benzoylacetone with Ti ions are formed in the Ti1−x Co x O2 gel films. With irradiation of UV light, the chelate rings are photolyzed, which leads to a change of the solubility of the Ti1−x Co x O2 gel films in methanol. Based on this, the micro-patterns of Ti1−x Co x O2 gel films are obtained. After the patterned gel films are dried at 200°C and are fired at 550°C for 1h, negative patterned Ti1−x Co x O2 inorganic films are obtained. The Ti1−x Co x O2 films have an anantase structure and exhibit a room temperature ferromagnetic property. [ABSTRACT FROM AUTHOR]

Abstract: Using yttrium, barium and copper acetates as starting materials, fluorine-free YBCO precursor solution is prepared by the chemical complexation approach with diethylenetriamine, lactic acid, and α-methacrylic acid as complexing agents. Using the stable precursor solution, YBCO gel films are coated on LaAlO3 substrate by the dip-coating method. Effect of different heat treatment processes on the phase evolution and final film properties are examined. Results indicate that, either in a dry or in a humidified atmosphere, it is difficult to obtain high-performance YBCO films by a traditional pyrolysis–annealing process, due to the formation of stable BaCO3 phase during the pyrolysis process. On the contrary, using the fluorine-free precursor solution, epitaxial YBCO films with high Tc (>94K) and Jc (>1MA/cm2) can be obtained using a direct annealing process without pyrolysis process. [ABSTRACT FROM AUTHOR]

Abstract: Er-doped ZnO films were deposited by direct current co-reactive magnetron sputtering technique and the microstructure and the optical properties of the ZnO films were investigated. XRD analysis reveals that the substrate temperatures have an evident effect on the (002) preferential orientation and the Er-doped ZnO film deposited at room temperature consists of an amorphous phase. The blue shift of the optical band gap was observed in the ZnO:Er films compared with undoped ZnO film, and the Er-doped ZnO film deposited at room temperature has the largest band gap (about 3.99eV). The main reason for the broadening of the band gap is attributed to the amorphous phase in the Er-doped ZnO film. Meanwhile, the red shift of the band gap in the ZnO:Er films deposited at high temperature was observed as the crystallinity of the fim became better. [Copyright &y& Elsevier]

Abstract: Size-monodispersed Fe70Co30 alloy clusters were obtained by a plasma-gas-condensation (PGC)-type cluster deposition method. The structural and magnetic characteristics of Fe70Co30 alloy cluster-assembled films were systematically studied. The as-obtained Fe70Co30 clusters have a body-centered-cubic (bcc) α-(Fe,Co) structure and their average sizes can be adjusted from 8 to 14nm. Based upon the temperature dependence of magnetic coercivity, we estimated the effective magnetic anisotropy constant, K eff, and magnetic exchange length, L ex, as a function of initial mean cluster diameter, d, in the Fe70Co30 cluster-assembled films which were formed by soft landing of the clusters and have a low cluster-packing fraction of about 30%. The estimated K eff and L ex values depend strongly on the d values of the cluster-assembled films: K eff decreases while L ex increases with decreasing d of the Fe70Co30 clusters. For the Fe70Co30 cluster-assembled films with d =14.3nm, the L ex value is close to the initial mean cluster size, whereas for the films with d =9.7nm the L ex value is about two times of the initial mean cluster size. [Copyright &y& Elsevier]

Permalloy (Py) films were deposited on Si(111) or Corning 0211 glass substrates. There were two deposition temperatures: T =room temperature (RT) and T =270°C. The film thickness ( t ) ranges from 10 to 130 nm. The crystal structure properties of the films were studied by X-ray diffraction and transmission electron microscopy. Mechanical properties (including Young's modulus E and hardness H ) of each film were measured by the nanoindentation (NI) technique. E of the Py/Si(111) films was checked again by the laser induced surface acoustic wave (LA-SAW) technique. It was found that the NI technique is best suited for the measurements of E and H , but only when the sample belongs to the (soft film)/(soft substrate) system, such as the Py/glass film. For the (soft film)/(hard substrate) system, such as the Py/Si(111) film, the NI technique often provides higher values of E and H than expected. The anomalous phenomenon, associated with the NI technique may be related to the anisotropic crystal structures in the Py films on different kinds of substrates. From this study, we conclude that [ E of Py/Si(111)]>[ E of Py/glass] and [ H of Py/Si(111)]>[ H of Py/glass]. The good mechanical properties of the Py/Si(111) film make it a better candidate for recording head applications. [ABSTRACT FROM AUTHOR]

The effects of annealing environment on the luminescence characteristics of ZnO thin films that were deposited on SiO2/Si substrates by reactive RF magnetron sputtering were investigated by X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). An analysis of the O 1s peak of ZnO film revealed that the concentration of oxygen vacancies increased with the annealing temperature from 600 °C to 900 °C under an ambient atmosphere. The PL results demonstrated that the intensity of green light emission at 523 nm also increased with temperature. Under various annealing atmospheres, the analyses of PL indicated that only one emission peak (523 nm) was obtained, indicating that only one class of defect was responsible for the green luminescence. The green light emission was strongest and the concentration of oxygen vacancies was highest when the ZnO film was annealed in ambient atmosphere at 900 °C. The results in this investigation show that the luminescence mechanism of the emission of green light from a ZnO thin film is associated primarily with oxygen vacancies. [ABSTRACT FROM AUTHOR]

Abstract: Tetrahedral amorphous carbon (ta-C) film was coated on aligned carbon nanotube (CNT) films via filtered cathodic vacuum arc (FCVA) technique. Field electron emission properties of the CNT films and the ta-C/CNT films were measured in an ultra high vacuum system. The I–V measurements show that, with a thin ta-C film coating, the threshold electric field (E thr) of CNTs can be significantly decreased from 5.74 V/μm to 2.94 V/μm, while thick ta-C film coating increased the E thr of CNTs to around 8.20 V/μm. In addition, the field emission current density of CNT films reached 14.9 mA/cm2 at 6 V/μm, while for CNTs film coated with thin ta-C film only 3.1 V/μm of applied electric field is required to reach equal amount of current density. It is suggested that different field emission mechanisms should be responsible for the distinction in field emission features of CNT films with different thickness of ta-C coating. [Copyright &y& Elsevier]

ZnO thin films deposited on SiO2/Si substrates at room temperature by sputtering technology were annealed with a rapid thermal annealing process at various temperatures from 200 °C to 900 °C. The physical and optical properties of the ZnO films were investigated by X-ray diffraction, scanning electron microscopy and room-temperature photoluminescence (PL). The surface structures of the thin films showed great variations with increased annealing temperature. The PL spectrum illustrated that a stronger UV emission intensity appeared at an annealing temperature of 500 °C. On the other hand, visible-light emission could be obtained when the ZnO films were annealed above 500 °C and reached a maximum intensity at 900 °C. The possible mechanisms for visible-light emission are discussed. [ABSTRACT FROM AUTHOR]

The effects of plasma treatment of textured substrates on orientation ratio (OR) as well as in-plane Cr(200)/Co(11.0) preferred orientation (PO) and coercivity (Hc) in longitudinal magnetic recording media have been systematically investigated. OR is found to increase by ~0.2-0.3 with enhanced PO and Hc for samples with slightly rf sputter etched substrates. Further Ar+ plasma dry etching (higher power/longer duration) leads to a slow decrease of OR to =1, then a worsened/vanishing PO and finally a drastic drop in Hc. The origin of OR is primarily attributed to stress effects (of most importance being the anisotropic stress induced preferential easy axis distribution), with anisotropic topography and PO as two necessary preconditions for OR>1. Ion beam bombardment induced chemical/structural modifications and residual stress in the substrate surface layer may play important roles in film growth/structures/properties and therefore in the mechanisms of the evolution of OR with plasma treatment. [ABSTRACT FROM AUTHOR]

SrBi[sub 2]Ta[sub 2]O[sub 9](SBT)/LaNiO[sub 3](LNO)/Si and SBT/Pt/TiO[sub 2]/SiO[sub 2]/Si multilayers were fabricated by pulsed laser deposition. With Pt top electrodes, the measured remanent polarization (2P[sub r]) of Pt/SBT/LNO/Si and Pt/SBT/Pt/TiO[sub 2]/SiO[sub 2]/Si capacitors was 6.5 μC/cm[sup 2] and 5.2 μC/cm[sup 2], respectively. Using LNO as both bottom electrodes and buffer layers, enhanced non-c-axis crystalline SBT films were induced, which resulted in a 2P[sub r] greater than that of the Pt/SBT/Pt/TiO[sub 2]/SiO[sub 2]/Si capacitor. The hysteresis loop of the Pt/SBT/LNO/Si capacitor showed a great external-field-dependent horizontal shift. Using an electron-injection model, this dependence was addressed. The fatigue-free property of the Pt/SBT/LNO/Si capacitor was experimentally established, in that the non-volatile polarization decreased by less than 5% of the initial value after 1.44×10[sup 9] switching cycles . [ABSTRACT FROM AUTHOR]

(001) textured PbTiO[sub 3] thin films have been deposited on (001) redoping n-Si substrates by metalorgnic chemical vapor deposition (MOCVD) under reduced pressure, and the film ferroelectricity has been measured using the substrate as bottom electrode directly. Besides this investigation, a set of analysis including AFM surface morphology, SEM cross section morphology, electron-probe element analysis, XRD θ-2θ scan and high temperature X-ray diffraction have been carried out to study the microstructure and phase transition process of the PbTiO[sub 3] thin film. [ABSTRACT FROM AUTHOR]

The polycrystalline BaTiO3 (BTO) thin films were grown on F-doped SnO2 substrates by pulsed laser deposition. The devices show a rectification at a small voltage, while bipolar resistive switching (RS) and negative differential resistance (NDR) appear at a large voltage. Furthermore, RS remains and NDR disappears when no positive bias is applied, while both RS and NDR behaviors improve when increasing the positive bias. The electrons trapped/detrapped by interface states at Au/BTO interface are proposed to understand the above behaviors. [ABSTRACT FROM AUTHOR]

Thin films are widely used in microelectronics, optics, filters, and various sensing devices. We propose a method to simultaneously determine the elastic modulus and density or thickness of ultrathin films deposited on various substrate materials. This methodology utilizes measurement of the resonant frequencies of the micro-/nanoresonator under intentionally applied axial tension and, consequently, the beam to string transition. Elastic modulus and density/thickness of thin film are obtained from the ratio between the resonant frequencies of the nanoresonator with and without applied axial force. [ABSTRACT FROM AUTHOR]

By high temperature microscopy, we conducted in-situ observation on the evolution of peritectic melting of YBa2Cu3O7-y thin films (denoted as the α phase). As the α phase was highly superheated above a critical temperature, we found that a non-equilibrium phase transition occurred. An unexpected metastable Y2O3 phase (denoted as the γ phase), resulted from the decomposition of the α film, nucleated preferentially to the stable phase of Y2BaCuO5 (denoted as the β phase). Both high superheating capability of the α film and low interface energy of the γ phase with substrates are responsible for the metastable phase transition in this work. [ABSTRACT FROM AUTHOR]

The temperature and magnetic field dependence of angular dependent magnetoresistance (AMR) along two orthogonal directions ([100] and [formula]) was investigated in a charge-orbital-ordered Sm0.5Ca0.5MnO3 (SCMO) film grown on (011)-oriented SrTiO3 substrates. A dramatic decrease of AMR magnitude in both directions was observed with the appearance of magnetic-field-induced metal-insulator transition, which further led to a sign crossover in the AMR effect. The AMR crossover may give a direct evidence of the drastic modification of electronic structure or possible orbital reconstruction with the magnetic-destruction of charge/orbital ordering in SCMO films. [ABSTRACT FROM AUTHOR]

Two clear phase transitions, an insulator to metal transition followed by a metal to insulator transition on cooling, were realized in La1-xSrxMnO3 (x∼1/8) (LSMO) thin films grown on (011) SrTiO3 substrates due to the substrate-imposed anisotropic stain. Effects of phase transitions on the rectifying behavior of the corresponding junction LSMO/Nb:SrTiO3 were further investigated. The paramagnetic/insulator to ferromagnetic/metal transition led to a decrease in built-in potential of the junction, while the metallic to charge/orbital ordering transition results in a growth of interfacial barrier, which could be explained by Fermi-level shifts and the gap opening/closing in LSMO films. These results indicate the occurrence of clear phase transitions in the vicinity of interface in (011)-LSMO films. [ABSTRACT FROM AUTHOR]

High temperature ferromagnetism and perpendicular magnetic anisotropy were observed in Fe-doped In2O3 magnetic semiconductor films deposited on R-cut sapphire by pulse laser deposition. The films show a Curie temperature as high as 927 K. Strong perpendicular magnetic anisotropy with a remnant magnetization ratio of 0.77 and a coercivity of 680 Oe is demonstrated. Extensive microstructure, composition, and magnetic studies indicate that Fe element incorporates into the indium oxide lattice by substituting the position of indium atoms, which suggests the observed ferromagnetism is intrinsic rather than from Fe clusters or any other magnetic impurity phases. [ABSTRACT FROM AUTHOR]

We have studied the microstructure and strain relaxation of epitaxial PrScO3 films grown on miscut (001) SrTiO3 substrates by transmission electron microscopy. PrScO3 films grown on highly miscut (>1°) SrTiO3 substrates are single domain films, fully strain relaxed via interfacial misfit dislocations, small angle tilt boundaries, and antiphase boundaries bounded by partial dislocation. In contrast, strain in PrScO3 films on low miscut (<0.2°) SrTiO3 substrates is relaxed by misfit dislocation as well as the formation of six different crystallographic domains. The formation of single domain PrScO3 films on high angle miscut substrates could be due to interfacial strain-energy minimization. [ABSTRACT FROM AUTHOR]

Ferroelectric domain structures of epitaxial BiFeO3 thin films on miscut (001) SrTiO3 substrates have been studied by transmission electron microscopy. BiFeO3 on 0.8° miscut substrates are composed of both 109° and 71° domains; in contrast, only 71° stripe domains are observed in BiFeO3 on 4° miscut (001) SrTiO3 substrates. The domain width in BiFeO3 on 4° miscut substrates increases as film thickness increases due to a reduction in domain wall energy. The domain configurations of BiFeO3 thin films affect their ferroelectric switching behavior due to the pinning at the junctions between 109° and 71° domain walls. [ABSTRACT FROM AUTHOR]

Highly sensitive surface acoustic wave (SAW) humidity sensors were fabricated by spin-coating polyvinyl-alcohol (PVA) thin film on the SAW resonators. The transmission properties of the SAW sensor, including centre frequency and insertion loss, were investigated at a relative humidity ranging from 30 to 90%. The results justify the suitability for the PVA film coated SAW resonators in the application of sensing humidity at a higher relative humidity. [ABSTRACT FROM AUTHOR]

Thin film transistors are fabricated by in situ growth of SnO2 nanobelts on Au/Pt electrodes. A linear correlation in the output characteristics is observed at zero gate voltage, indicating Ohmic contacts between the nanobelts and the electrodes. The transistors exhibit n-type behaviors and have a mobility of 1.85 cm2/V s with a current on/off ratio above 103. The conductance increases as the pressure in the device chamber is reduced, which indicates that the transistors are promising for oxygen detecting. [ABSTRACT FROM AUTHOR]

Epitaxial growth of high piezoelectric constant Pb(Zr0.525, Ti0.475)O3 (PZT) thin films deposited on amorphous magnetic Metglas® substrates by pulsed laser deposition (PLD) is reported. Particularly, Pt or Au buffer layers were employed to initiate epitaxial growth of the PZT films from atop of an amorphous surface. The optimization of deposition conditions for the PZT films with different buffer layers was systematically investigated. The crystal structure, texturing, and surface morphology of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ferroelectric and piezoelectric properties were measured indicating high polarization 27 μC/cm2 and piezoelectric constant d33, 46 pm/V for the Pt buffered films. The PZT thin films grown on a magnetostrictive material have demonstrated high quality crystallographic structure and piezoelectric response, having potential for use in emerging magnetoelectric sensors. [ABSTRACT FROM AUTHOR]