Sublattice magnetization and cation distribution in BaMg2Fe16O27(Mg2W) ferrite

Mössbauer measurements were carried out in compound BaMg2Fe16O27(Mg2W) by utilizing both polycrystalline and single-crystal samples. The resonant γ-absorption spectra have been measured with the absorbers at temperatures of 85 to 800°K and in some cases in the presence of a 15-kOe external magnetic field. The values of the hyperfine magnetic fields Hhfat the Fe⁵⁷nuclei in the different sublattices as functions of temperature have been measured. By fitting the curve of the saturation magnetization σ versus temperature, the cation distribution over the available lattice sites has been deduced. From the value of σ extrapolated at 0°K, it turns out that the number of Bohr magnetons(n_{B})Wper elementary cell is higher than the value obtained by adding the corresponding values for theSandMstructures. The Curie temperature of the compounds has also been measured and is equal to (440 ± 5)°C.