Magnetic properties of double perovskite Ca₂FeMoO₆ by neutron diffraction and Moessbauer spectral studies

Crystallographic and magnetic properties of the double perovskite oxide Ca₂FeMoO₆ were studied. The single phase polycrystalline Ca₂FeMoO₆ powder was prepared by a solid-state reaction method. The crystal structure of the Ca₂FeMoO₆ is found to be monoclinic with lattice constants a₀ = 5.4056 Å, b₀ = 5.5170 Å, c₀ = 7.6971 Å, and β = 89.92°. The Moessbauer spectra have been taken at various temperatures ranging from 17 to Curie temperature (T_C) was found to be 350 K. The isomer shift value at room temperature is 0.43 mm/s relative to the Fe metal that are consistent with the Fe³⁺ valence state. Hyperfine parameters of the Moessbauer spectra were analyzed as a function of temperature and observed the magnetic properties with crystallographic changes through neutron diffraction experiments. (author)