Structure and physical properties of double perovskite compounds Sr2FeMO6 (M = Mo, W)

The crystal structure and physical properties of the Sr2FeMO6 (M = Mo, W) double perovskite have been investigated. Analysis of the X-ray powder diffraction pattern based on Rietveld refinement indicates that Sr2FeMoO6 and Sr2FeWO6 have tetragonal cell (space group: I4/m) and orthorhombic cell (space group: Immm), respectively. The Curie–Weiss fit for Sr2FeWO6 gives Curie constant, C = 6.08 and Weiss temperature, θ = −32.6 K. The small and negative value of θ suggests the existence of both weak ferromagnetic and antiferromagnetic interactions at low temperature. The antiferromagnetic interaction dominates over the weak ferromagnetic one.