Palladium and platinum phosphochalcogenides—Synthesis and properties

Abstract

Three new PdP y S 2− y (0 < y ⩽ 1) compounds have been prepared between the known end members, PdP 2 and PdS 2, as well as certain selenide isotypes. The semiconductors, PdPS (orthorhombic, P2 1 ca or Pmca) and PdPSe, were obtained from the elements by reaction at autogenous pressure. The metallic, pyrite-type compounds PdP 0.67S 1.33 and PdP 0.59Se 1.41, as well as a second metallic type phase of approximate composition PdP 0.33S 1.67, were prepared under high pressure in a tetrahedral anvil device. The unrelated thiophosphate Pd 3(PS 4) 2 (trigonal, P 3m1 ) was also obtained at autogenous pressure. The crystal structure of this semiconductor was solved by refinement of X-ray powder intensity data using trial and error methods. Reactivity was much lower in the related Pt systems and only substitution of small amounts of S for P in pyrite-type PtP 2 was observed.