Structural, Mössbauer spectroscopy, magnetic properties, and thermal measurements of Y_3-xDy_xFe₅O₁₂

Yttrium iron garnet powder samples (Y_3-xDy_xFe₅O₁₂), where part of yttrium ions are substituted by dysprosium ions with different concentrations are prepared by the solid state reaction method. The properties of the prepared samples are examined by different methods such as x-ray diffraction (XRD), Mössbauer spectroscopy, macroscopic magnetization measurements, and thermal measurements. The XRD measurements show that all the samples reveal the presence of a single garnet phase with a BCC structure. Room temperature Mössbauer spectra indicate that iron ions occupy three magnetic sites, i.e., two octahedral sites and one tetrahedral site. The saturation magnetization and the initial magnetic susceptibility decrease with the increase of Dy³⁺ substitution. The Curie temperature obtained from the thermal measurements seems to be independent of Dy³⁺ substitution.