Alloys with Arsenic

Abstract

No phase diagram has been determined. However, a number of intermediate compounds have been identified, and some structures and lattice parameters determined. The existence of RhAs, RhAs₂, Rh₂As and RhAs₃ was established by [1]. A polymorphic transformation in Rh₂As which took place between 650 and 700 °C was found during an investigation of the system at temperatures between 300 and 1000 °C no Liquid phases were found up to 1000 °C at the rhodium-rich end, and none up to 900 °C at the arsenic-rich end. A new phase was found at Rh_{1 7}As and a homogeneous field between Rh_{1 3}As and Rh_{1 6}As [2]. Investigations by X-ray diffraction and density determinations on the compound RhAs₂ confirmed the approximate CoAs₂-type structure [3]. Lattice parameter measurements were made on Rh₂As with material quenched from above and below the transformation temperature and also, the magnetic susceptibility was measured with rising and decreasing temperature on the α and β forms; the latter measurements suggested that the transformation takes place between 870 and 890 K [4]. The compound RhAs₃ has been examined by [5].