Comparative Study on the Magnetic and Transport Properties of B-Site Ordered and Disordered CaCu 3 Fe 2 Os 2 O 12 .

The B-site Fe/Os ordered and disordered quadruple perovskite oxides CaCu 3 Fe 2 Os 2 O 12 were synthesized under different high-pressure and high-temperature conditions. The B-site ordered CaCu 3 Fe 2 Os 2 O 12 is a system with a very high ferrimagnetic ordering temperature of 580 K having the Cu 2+ (↑)Fe 3+ (↑)Os 5+ (↓) charge and spin arrangement. In comparison, the highly disordered CaCu 3 Fe 2 Os 2 O 12 has a reduced magnetic transition temperature of about 350 K. The Cu 2+ Fe 3+ Os 5+ 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 CaCu 3 Fe 2 Os 2 O 12 against site disorder may be taken as an indication of the tendency to maintain the short-range order of the atomic constituents.