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High-k gate dielectric HfO thin films have been deposited on Si and quartz substrates by radio frequency magnetron sputtering. The structural characteristics, surface morphology, and optical properties of the HfO/Si gate stacks at various post-annealing temperatures were examined by X-ray diffraction (XRD), atomic force microscopy (AFM), fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis spectroscopy), and spectroscopic ellipsometry (SE). XRD measurement indicates that the 80 W-deposited HfO films demonstrate a polycrystalline structure. AFM measurements illustrate that the root mean square of the HfO thin films demonstrates an apparent increase with increasing the annealing temperature. Analysis from FTIR indicates that the Si-O-Si bonds vibration peak position shift toward lower wave numbers with increasing the annealing temperature. Combined with UV-Vis spectroscopy and SE measurements, it can be noted reduction in band gap with an increase in annealing temperature has been confirmed. Additionally, increase in refractive index ( n) has been confirmed by SE. [ABSTRACT FROM AUTHOR]

The amorphous gallium nitride thin films doped with Mn were deposited by Laser assisted Molecular Beam Epitaxy (LMBE). After annealing at different NH flow rates, the high-quality GaMnN crystalline films with different concentration of nitrogen vacancies ( V) were obtained, which were confirmed by the X-ray diffraction spectroscopy and Raman measurements. The magnetic behaviors of these films were also obtained to investigate the effects of nitrogen vacancies. It indicates that V play a significant role in the origin of ferromagnetism. The stronger room-temperature ferromagnetism is given with the higher V concentration when it is not beyond a critical concentration. Moreover, from our M( T) curves and Raman analysis, the films present high resistivity. The magnetism of films with high resistivity varies with concentration of nitrogen vacancies, which can be explained by the bound magnetic polarons (BMP) theory. [ABSTRACT FROM AUTHOR]

GaFeO3 thin films were prepared on (111)-oriented SrTiO3:Nb substrates under various oxygen pressures from 0.1 to 10 Pa at 700 °C by using a pulsed laser deposition method. Effects of the oxygen pressures on the crystallinity, dielectric and ferroelectric properties of the thin films were investigated at room temperature. The results show that the GaFeO3 thin films exhibit ferroelectricity and the properties of the thin films are influenced markedly by the deposition oxygen pressures. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of heme proteins such as hemoglobin (Hb), myoglobin (Mb), and horseradish peroxidase (HRP) was studied in stable thin films composed of the proteins and a natural bacterial endotoxin (lipopolysaccharide, LPS). All three protein-LPS films exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks in pH 6.0 phosphate buffers. Moreover, hydrogen peroxide and trichloroacetic acid could be reduced catalytically by the proteins entrapped in the films. Electrochemical parameters, such as the apparent Michaelis-Menten constant ( K app m) and formal potentials ( E 0), were obtained. The positions of the Soret absorption band of the proteins suggested that the three proteins could keep their secondary structure in LPS films. [ABSTRACT FROM AUTHOR]

Abstract. The nonlinear optical properties of a new polymeric material, the doped film of 4'-(2",4",6"-trichlorophenazoamino)-phenazo-4-nitrobenzene, was studied. Large nonresonant optical nonlinearity (chi[sup (3)] is greater than or equal to 10[sup -28]C[sup 4]m/J[sup 3] or 10[sup -9] esu) and fast response time (t < 20 ps) were measured by forward degenerate four-wave mixing experiment. Optical bistable behavior in a quasi-waveguide interferometer with the thin film of the material was observed. The potential of the material for optical switching was evaluated. [ABSTRACT FROM AUTHOR]