Cation distribution in Ba2(Fe,W0.5Mo0.5)2O6 double-perovskites: A combined synchrotron and neutron diffraction, magnetization and Mössbauer spectroscopy study

The crystallographic and magnetic structures of polycrystalline Ba2(Fe,W)2O6 and Ba2(Fe,W0.5Mo0.5)2O6 double-perovskites have been investigated by X-ray and neutron powder diffraction (NPD), magnetization and Mössbauer spectroscopy. The samples were synthesized by conventional solid-state reaction at temperatures about 1273 K. The compounds crystallize in the cubic structure with space group Fm3¯m. The magnetic structures were determined by neutron powder diffraction between 5 K and 310 K. Evidence for an antiferromagnetic behavior has been observed for Ba2(Fe,W)2O6 with TN = 24.7 K and a two-phase separation for Ba2(Fe,W0.5Mo0.5)2O6 into an antiferromagnetic structure of the W-type with TN = 24.7 K and the ferromagnetic Mo-type with TC = 270 K.