Crystal structure and magnetic properties of double perovskite Mn2FeSbO6

The double perovskite Mn2FeSbO6 has been synthesized under pressure 6 GPa and temperature 1000 °C. The crystal structure refinement of Mn2FeSbO6 was carried out with the GSAS program suite using X-ray diffraction data. XRD pattern of Mn2FeSbO6 was indexed with a monoclinic unit cell (space group P21/n) with parameters: a = 5.2431(3) Å, b = 5.3935(3) Å, c = 7.6358(5) Å, β = 89.693(2)°, V = 215.927 Å3, Z = 2. It found that Fe and Sb atoms are completely ordered in 2d and 2c positions of double perovskite structure respectively. According to XPS measurements, manganese in this compound is present as Mn2+, whiles the iron – as Fe3+. Magnetization measurements revealed the presence about 3 mass% of ferromagnetic impurity in the sample. Dependence of AC susceptibility χ″ from temperature showed that magnetic properties compound are determined probably by transformation in antiferromagnetic state below 19.5 K.