CRYSTAL AND MAGNETIC STRUCTURE OF PrCaCrO4

摘要

The crystal and magnetic structures of PrCaCrO4 have been characterized by high-resolution neutron diffraction. The structure is described as orthorhombic with space group Bmab and lattice parameters a=5.3909(3) angstroms, b=5.3999(3) angstroms, and c=11.9932(5) angstroms at 200 K. The antiferromagnetic ordering in the Cr3+ sublattice is explained on the basis of a propagation vector k=0 and a collinear structure, described within a symmetry mode Gx and a magnetic moment of 2.38(9) mu B at 1.5 K. The Neel temperature is around 180 K from both neutron diffraction and magnetic susceptibility measurements. 19 refs.