Palladium Di-arsenide, PdAs₂

It was early observed that palladium combines with arsenic with evolution of heat, a brittle fusible alloy being formed. The Palladium Di-arsenide, PdAs₂, may be prepared in a pure form by heating a mixture of palladium chloride with an excess of arsenic in a current of hydrogen. It melts at 680° C. with loss of arsenic. The crystals have the pyrites structure, with a = 5.970 ± 0.004 A. It is not ferromagnetic. By repeated oxidation and reduction at 400° to 500° C. the arsenic is removed as arsenious oxide, leaving a residue of palladium; this method may be used for the analysis of the arsenides of any of the metals of the platinum group.