Copper sublattice ordering in layered CuMP2Se6 (M=In, Cr)

The structures of the lamellar selenodiphosphates CuMP2Se6 (M=Cr, In) are reexamined using powder diffraction and auxiliary techniques. Antiferromagnetic behavior observed in CuCrP2Se6 below 40 K is shown to be consistent with the existence of separate, triangular Cu and Cr sublattices rather than a random cation distribution. Analyses of neutron powder diffraction patterns recorded at various temperatures for CuCrP2Se6 confirm this as well as...