Ikuhiro Yamaguchi

Thin-Film Gd 4 Bi 3 Grown on a Glass Substrate

Sputtered thin-films of Gd-Bi (4:3 in atomic ratio) were annealed in vacuum under various annealing conditions. The samples annealed at a temperature near 530°C and 4 hours contained 40% of poly-crystalline Gd 4 Bi 3 phase, which is of the anti-Th 3 P 4 structure. The main peak in the x-ray diffraction spectrum due to Gd 4 Bi 3 is of (310). The phase of Gd 4 Bi 3 was not found for a lower annealing temperature; for a higher annealing temperature (above 550°C), this phase could not be observed, because other phases or structures were beginning to grow, e. g. Gd 5 Bi 3 and/or GdBi phases. The Curie temperature of the Gd 4 Bi 3 thin-films was estimated to be about 330 K; this value is nearly the same as that of bulk Gd 4 Bi 3 . The residual resistance of the Gd 4 Bi 3 thin-films was several times as large as that of bulk Gd 4 Bi 3 poly-crystal.