The crystal structure of the low temperature form of Co2As

Abstract

The low temperature (α) form of Co₂As has been investigated by single-crystal X-ray methods. It crystallizes in a hexagonal unit cell. The space group is $\text{P}\text{6}\text{2m}$ (number 189), with lattice parameters $\text{a = 11.9821(7)}\text{A}\text{̊}$ and $\text{c = 3.5822(5)}\text{A}\text{̊}$ and Z = 12. The crystal structure is closely related to, but distinctly different from, the high temperature Fe₂P-type structure.