A study of some palladium-indium, platinum-indium and platinum-tin alloys

Abstract

The room temperature lattice spacings and magnetic susceptibilities of some PdIn alloys, and the room temperature lattice spacings of some PtIn and PtSn alloys, have been examined in the present work. Extensive primary solid-solubility of indium and tin in α-palladium and α-platinum has been found and whereas indium expands the lattice of α-palladium to a slightly greater extent than tin, in the α-platinum solid solutions, larger expansions were obtained in the case of the tin alloys. The phases Pt 3Sn and Pt 3In have the ordered L12-type structure whereas Pd 3In has a face-centred tetragonal (f.c.t.) structure but is face-centred cubic (f.c.c.) in the deformed (as-crushed) state. It was not possible to determine whether Pd 3In is ordered because of the closely similar scattering factors of palladium and indium. The axial ratio of tetragonal Pd 3In decreases with increasing temperature. The magnetic susceptibilities of the α PdIn alloys have been correlated with the effective valency of the alloys and deviations from the behaviour expected from the simple rigid band model occur at indium contents in excess of 8 at.% ∗ ∗ All percentage compositions in this paper refer to atomic percent. . The PdIn B2-type phase exists over an appreciable composition range (~16 at.%), and the variation of the lattice spacings over this range indicated that constitutional vacancies are probably formed at indium contents in excess of 50 at.%. The structures and lattice spacings of the phases Pd 2In 3, PdIn 3, PtSn and PtSn 2 have also been determined in the present work.