Solid Solutions of Pauli-Paramagnetic CaCu3V4O12 and Antiferromagnetic CaMn3V4O12

Abstract

Solid solutions of Pauli-paramagnetic CaCu3V4O12 and antiferromagnetic CaMn3V4O12 were prepared by a high-pressure synthesis technique. All samples crystallized in the A-site-ordered perovskite structure with isovalent Cu(2+) and Mn(2+) ions at the square-planar A' site. The V ion at the B site kept a charge state close to +4 in all of the solid solutions, and the electrons of V were delocalized and contributed to the metallic properties. The substitution of Mn(2+) for Cu(2+) in CaCu3V4O12, where both Cu and V electrons were delocalized, produced the S = 5/2 localized moments, and the spins at the Mn site interacted antiferromagnetically. Spin-glass-like magnetic behaviors due to the random distribution of Cu/Mn ions at the A' site were observed at intermediate compositions of the solid solution, whereas the antiferromagnetic transition was observed at the end composition CaMn3V4O12.