Electronic state of Fe in double perovskite oxide Sr2FeWO6

The magnetic properties of double perovskite oxide Sr2FeWO6 have been reported. The magnetic susceptibility and Mossbauer effect of Fe-57 show that this compound is an antiferromagnet with T-N = 37 K. The Mossbauer parameters below similar to 20 K are the center shift of + 1.2 mm/s relative to metallic iron, the quadrupole splitting of 1.9 mm/s and the hyperfine field of similar to 110 kOe. The quadrupole splitting has a strong temperature dependence. From these data, we conclude that Fe in Sr2FeWO6 is in the Fe2+ high-spin state, while the hyperfine field seems to be quite small. The cell volume shows a large increase compared to other Sr2FeTO6 (T = Mo, Re, etc.), which is in the Fe3+ high-spin state. These results suggest that these compounds have a strongly coupled charge and lattice systems.