It is well-known that quantitative analysis of major elements by SIMS is generally difficult because of the matrix effect. In the present paper we examined some basic problems of the major element analysis of CdxHg1-xTe (CMT) which is known to be easily damaged by various kinds of beams. It was shown that the matrix effect in quantification can be reduced by detecting postionized monoatomic ions for O2+ and Ar+ primary beams. In the case of Cs+ bombardment, detection of the cationized molecular ions, which are formed via one kind of post-ionization process, also proved to be effective. In all the cases, good linear relationships between the secondary ion intensity and the primary ion current density were obtained in the log-log plot. The intensity decrease of Hg+, however, was observed along with depth profiling of the bulk sample. This phenomenon was correlated with the morphological changes caused by ion irradiation.
Vibrational energy distributions in CO2 molecules formed by the catalytic oxidation of CO on Pt and Pd surfaces have been measured by using infrared emission spectroscopy. The reactants (the total flux of CO and O2: 1.3×1019 molecules/cm2·s) were supplied to the surface through two free jet nozzle sources, while an FT-IR spectrometer was used to obtain the infrared emission spectra (4 cm-1 resolution) of the product CO2. For all the experimental conditions (surface temperature in the range of 650∼1150K and O2/CO ratio from 5/1 to 1/5), the emission spectra observed in the 2400∼2100 cm-1 region were significantly red shifted from the fundamental of the asymmetric streth at 2349 cm-1, indicating that the CO2 molecules were vibrationally excited substantially beyond thermal equilibrium with the surface. The surface coverage of oxygen on both Pt and Pd was varied by changing the O2/CO ratio and, in both cases, increasing oxygen coverage caused an increase in the average vibrational temperature. This is in stark contrast with that by Brown and Bernasek who reported that the average apparent CO2 vibrational temperature decreased with increasing surface oxygen coverage. The average vibrational temperature was much higher on Pd than on Pt. This is in good agreement with that by Coulston and Haller who suggested that the activated complex is bent more on Pd than on Pt.
When TiO2 semiconductor electrode was irradiated in electrolytic solution containing Ir2 (SO4)3, a thin film of iridium oxide was selectively formed at the irradiated region. Property of the deposited films was examined by XPS, SEM and electrochemical measurement. It was concluded that the deposition of the iridium oxide was caused by electrochemical oxidation by means of photoexited holes of the n-type semiconductor electrode.