Crystal and Magnetic Structure of PrCaCrO4

The crystal and magnetic structures of PrCaCrO4have been characterized by high-resolution neutron diffraction. The structure is described as orthorhombic with space groupBmaband lattice parametersa=5.3909(3) ?,b=5.3999(3) ? , andc= 11.9932(5) ? 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 modeGxand a magnetic moment of 2.38(9)MU Bat 1.5 K. The Néel temperature is around 180 K from both neutron diffraction and magnetic susceptibility measurements.