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

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.