Strong ferromagnetism and weak antiferromagnetism in double perovskites:: Sr2FeMO6 (M = Mo, W, and Re) -: art. no. 180407

Double perovskites Sr2FeMO6 (M = Mo and Re) exhibit significant colossal magnetoresistance even at room temperature due to the high Curie temperatures (419 and 401 K). However, such a high Curie temperature is puzzling, given the large separation between magnetic elements (Fe). Moreover. with M = W, the electronic and magnetic properties suddenly change to insulating and antiferromagnetic with the Neel temperature of only 16 similar to 37 K. Based on detailed electronic structure calculations. a mechanism is proposed which stabilizes the strong ferromagnetic state for M = Mo and Re and is passivated for M = W.