Toshiharu Shimazaki

Investigation of double oxides in the system of Pr2O3–WO3

Powdered samples composed of Pr2O3 and WO3 in various mixing mole ratios were heat-treated in an air flow or in an N2 gas flow at 1000°C. The phases formed in the samples were investigated by XRD. Single phases of the five double oxides of the mole ratios Pr2O3:WO3 of 1:4.4, 1:3, 1:2, 1:1, and 5:2 were obtained at the respective mixing mole ratios by a reaction in air. The single phase of 3:1 oxide, which was reported to be obtained in a vacuum or an Ar atmosphere, was not obtained by a heat treatment in air but rather by a reaction in an N2 atmosphere. Furthermore, the crystal system and the lattice parameters were determined for the double oxides with the mole ratios of 1:4.4, 1:3, 1:1, and 5:2.

Impurity-Doped GaSe Radiation Detector Evaluated at 100°C

The pulse height distribution for 5.5 MeV α particles from 241Am was measured using a GaSe detector doped with 0.1 at.% Sn at 100°C and compared with that measured at room temperature. It was found that the energy resolution at 100°C was 8.3% which was as good as that at room temperature. The temperature dependence of the leakage current of the detector was also measured for the applied voltage of 50 V and found to have a small value of 60 nA at 100°C.

Pattern Formation of Sputtered Films by Deposition through Mask

The thickness of the film near the edge of a film pattern formed by sputter deposition through a mask is not uniform, because of the shadowing effect of the side wall of the mask edge. When the effect is large, a sharp pattern can not be obtained. In order to clarify the precision or the sharpness of the film pattern, the distribution of the film thickness near the pattern edge was measured. It was found that the sharpness depended on the position of the pattern edge and the attitude of the side wall of the mask. A mask with bridges was contrived for the formation of an isolated space in a film, and the film deposition under the bridge was observed. It was found that the ratio of the gap between the substrate and the bridge to the bridge width must be larger than 1.0 for the thickness under the bridge to be greater than half the full thickness.