Hole Transport in p-Type ZnO

A two-band model involving the A- and B-valence bands was adopted to analyze the temperature dependent Hall effect measured on N-doped \textit{p}-type ZnO. The hole transport characteristics (mobilities, and effective Hall factor) are calculated using the ``relaxation time approximation'' as a function of temperature. It is shown that the lattice scattering by the acoustic deformation potential is dominant. In the calculation of the scattering rate for ionized impurity mechanism, the activation energy of 100 or 170 meV is used at different compensation ratios between donor and acceptor concentrations. The theoretical Hall mobility at acceptor concentration of $7 \times 10^{18}$ cm$^3$ is about 70 cm$^2$V$^{-1}$s$^{-1}$ with the activation energy of 100 meV and the compensation ratio of 0.8 at 300 K. We also found that the compensation ratios conspicuously affected the Hall mobilities.Comment: 5page, 5 figures, accepted for publication in Jpn. J. Appl. Phy

Construction and Superfunction of Metal-oxide Nanostructures and Interfaces(Interfaces by various techniques)

Metal oxides show such versatile properties as high T_C superconductivity, ferroelectricity, colossal magnetoresistance and non-linear optical properties. By developing laser molecular beam epitaxy, we have been working on atomic scale control for the heteroepitaxy of these materials in order to explore a novel field of "oxide electronics", in which monolithically integrated devices composed of epitaxially grown oxide nanostructures show outstanding performances that Si-based semiconducting devices would not be able to give. Among many topics we have, we concentrate on Josephson tunnel junction made out of high T_C superconductors and ultra-violet laser emission from ZnO nanocrystal films

Molecular dynamics simulation on a layer-by-layer homoepitaxial growth process of SrTiO3(001)

科研費報告書収録論文(課題番号:09355030・基盤研究(A)(2)・H9～H11/研究代表者:宮本, 明/次世代エレクトロニクス材料としての酸化物人口超格子の原子レベル設計と開発

Layer-by-layer heteroepitaxial growth process of a BaO layer on SrTiO3(001) as investigated by molecular dynamics

科研費報告書収録論文(課題番号:09355030・基盤研究(A)(2)・H9～H11/研究代表者:宮本, 明/次世代エレクトロニクス材料としての酸化物人口超格子の原子レベル設計と開発

Layer-by-layer homoepitaxial growth process of MgO(001)as investigated by molecular dynamics, density functional theory,and computer graphics

科研費報告書収録論文(課題番号:09355030・基盤研究(A)(2)・H9～H11/研究代表者:宮本, 明/次世代エレクトロニクス材料としての酸化物人口超格子の原子レベル設計と開発

Single crystalline ZnO films grown on lattice-matched ScAlMgO4(0001) substrates

科研費報告書収録論文(課題番号:09355030・基盤研究(A)(2)・H9～H11/研究代表者:宮本, 明/次世代エレクトロニクス材料としての酸化物人口超格子の原子レベル設計と開発

Ureaplasma urealyticumの尿路感染に対するofloxacinの効果について

Ofloxacin was administered to 26 males infected with Ureaplasma urealyticum. The infection was confirmed by urine or semen culture. Ofloxacin, administered at daily dose of 300-600 mg for 7 to 28 days, eradicated U. urealyticum in 25 of 26 patients (92.2%)

Synthesis of Pd-Fe System Alloy Nanoparticles by Pulsed Plasma in Liquid

We synthesized Pd-Fe series nanoparticles in solid solution using pulsed plasma in liquid with Pd-Fe bulk mixture electrodes. The Pd-Fe atomic percent ratios were 1:3, 1:1, and 3:1, and the particle size was measured to be less than 10 nm by high-resolution transmission electron microscopy (HR-TEM). The nanoparticles showed face-centered cubic structure. The lattice parameter increased with increasing Pd content and followed Vegard’s law, and energy-dispersive X-ray spectra were consistent with the ratios of the starting samples, which showed a solid solution state. The solid solution structure and local structure were confirmed by HR-TEM and X-ray absorption fine structure

Transmission electron microscopy study of room temperature lasing epitaxial ZnO films on sapphire

We have studied the microstructures of lasing and non-lasing ZnO films on sapphire in plan-view and cross-section by transmission electron microscopy(TEM). While ZnO films in general are made up of cloumnar close-packed c-axis misoriented nanocrystals, the misorientation in nonlasing film, typically 5(0), is considerably larger than lasing film, typically less than 1(0). A rather high density of pinholes or nanotubes is associated with the highly misoriented films. The misorientation between adjacent grains is taken up by grain boundary dislocations. Room temperature lasing films contain a high density of threading boundary edge dislocations, in excess of 10(10) cm(-2). But faceting in the columnar nanocrystals is not well developed so that the grain boundaries are not clearly visible. Tilting of (0001) lattice planes between grains originating from substrate surface step and growth fault step, however, has been observed in high resolution electron microscopy (HREM) images