In this study, we report the growth and characterization of M-plane InN films on LiAlO2 (100) substrates by radio-frequency plasma assisted molecular beam epitaxy (RF-MBE). InN films were grown at various temperatures and under various V/III ratios on the substrates. Pure M-plane InN films were successfully grown at a high temperature of 450 degrees C and under a slightly In-rich condition, while the incorporation of C-plane phase was observed in M-plane InN films grown at low temperatures of less than 400 degrees C or under a N-rich condition. These indicate that controls of growth temperature and V/III ratio are important for the growth of pure M-plane InN films. The in-plane epitaxial relationships of M-plane InN on LiAlO2 (100) were [0001](InN) // [010](LiAlO2) and [1-210](InN) // [001](LiAlO2). A surface electron accumulation layer on the obtained M-plane InN film is also discussed. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

In this study, we characterized the microstructure of M-plane InN using transmission electron microscopy (TEM). The M-plane InN was grown on a (100) LiAlO2 substrate using radio-frequency plasma-assisted molecular beam epitaxy (RF-MBE). We determined the epitaxial relationships of the M-plane InN and LiAlO2 using selected area electron diffraction (SAED). The epitaxial relationships were exactly the same as the M-plane GaN grown on the same substrate. Also, the M-plane InN was grown on the (100) LiAlO2 despite the high lattice mismatches between M-plane InN and LiAlO2. We observed a high density of stacking faults parallel to (0001) InN. The density was estimated about 1.8 x 10(6) cm(-1), which was one order of magnitude higher than that of non-polar GaN. The correlation between threading dislocations and stacking faults is investigated. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Simulations with a quantum molecular dynamics (QMD) method ( MD with MO) were demonstrated on the thermal decomposition of lignin monomer at the ground state including excited and positive charged states. Geometry and energy optimized results of the lignin monomer at the singlet and triplet states in single excitation, and at (+2) positive charged state by semi-empirical AM1 MO calculations were used as the initial MD step of QMD calculations. In the QMD calculations, we controlled the total energy of the system using Nose-Hoover thermostats in the total energy range of 0.69-0.95 eV, and the sampling position data with a time step of 0.5 fs were carried out up to 5000 steps at 50 different initial conditions. The calculated neutral, positive and negative charged fragment distributions of the monomer model with 0.82 eV energy control were obtained as 90.6, 3.5, and 5.9% to the total fragments, respectively. The ratios seem to correspond well with to the values observed experimentally in SIMS. Crown Copyright (C) 2008 Published by Elsevier B. V. All rights reserved.

A high-density microwave plasma has been applied to the surface of polyimide (PI) films as a treatment to enhance the adhesion of sputter-deposited copper layers. A very short (∼5s) exposure to Ar plasma enhanced the contact angle from 72° to ∼14°. X-ray photoelectron spectroscopy and atomic force microprobe measurements showed an increase in hydrophilic radicals (–OH, –CO) and surface roughness, respectively, following the plasma treatment. Peel strength tests of Cu layers deposited on plasma-treated polyimide films showed that the plasma treatment significantly enhanced Cu layer adhesion.

In a conventional argon magnetron source using a planar cathode (target), numerous backscattered high-energy (100-200eV) argon atoms and ions impinge on a substrate, often causing damage in sputtered films. In order to reduce such energetic particles, a cylindrical magnetron source is proposed where most of the high-energy particles are confined inside a cylindrical cathode with low-energy particles impinge on the substrate outside the cylinder. Ar+ ion energy distributions of planar and cylindrical magnetron sources are measured using a mass spectrometer with an energy analyzer. In the cylindrical magnetron, a marked decrease in the energetic component is observed compared with that in the planar magnetron. A Monte Carlo code is developed to simulate energy distributions of Ar and Ar+ in the cylindrical magnetron source. Simulated Ar+ energy distributions are in good agreement with the measurements, reproducing the experimental results.

Magnetron discharge is maintained with very low target DC voltages (100-200 V) by applying 40 MHz VHF power to the target, without decreasing sputter deposition rate.From measurement of Ar+ energy distribution function (EDF) and simulation of Ar+ and Ar EDFs, it is confirmed that the VHF-DC magnetron discharge suppresses the maximum kinetic energy of backscattered Ar atom.This magnetron sputter source is applied to the deposition of magnetic multilayer film for perpendicular magnetic recording.From measurements of atomic force microprobe, the VHF-DC magnetron sputtering shows drastically-improved fil.m flatness, compared with conventional DC magnetron sputtering.

A hyperthermophophilic beta-1,4 endoglucanase (family 5, cellulase) was identified in a hyperthermophilic archaeon Pyrococcus horikoshii and found to be capable of hydrolyzing crystalline cellulose at high temperatures. This hyperthermophilic enzyme has promise for applications in biomass utilization, but we have no information regarding the catalytic mechanism or structure of the enzyme. To determine its catalytic mechanism, we examined the roles of amino acids located in a loop near the speculative active site by the alanine scanning method. Ten mutants of the enzyme were constructed and expressed in Escherichia coli. The purified mutant enzymes were assayed for their hydrolytic activities on p-nitrophenyl cellobiose (pNG2), carboxylmethyl cellulose, and avicel. The results showed that His155, Arg156, and Ile162 play an important role in pNG2 binding capacity, and that H155 and I162 are important for catalysis.