Comparative Study on the Magnetic and Transport Properties of B-Site Ordered and Disordered CaCu3Fe2Os2O12.

ABSTRACT

The B-site Fe/Os ordered and disordered quadruple perovskite oxides CaCu3Fe2Os2O12 were synthesized under different high-pressure and high-temperature conditions. The B-site ordered CaCu3Fe2Os2O12 is a system with a very high ferrimagnetic ordering temperature of 580 K having the Cu2+(↑)Fe3+(↑)Os5+(↓) charge and spin arrangement. In comparison, the highly disordered CaCu3Fe2Os2O12 has a reduced magnetic transition temperature of about 350 K. The Cu2+Fe3+Os5+ charge combination remains the same without any sign of changes in the valence state of the constituent ions. Although the average net moments of each sublattice are reduced, the average ferrimagnetic spin arrangement is unaltered. The robustness of the basic magnetic properties of CaCu3Fe2Os2O12 against site disorder may be taken as an indication of the tendency to maintain the short-range order of the atomic constituents.