Impact of In3+ cations on structure and electromagnetic state of M−type hexaferrites

Concentration dependence of the T f freezing and T div divergence temperatures for the SrFe 12- x In x O 19 samples. The solid solutions of In 3+ doped M-type strontium hexaferrites were produced using a conventional solid-state reaction method, and Rietveld analysis of the neutron diffraction patterns was conducted. In 3+ cations occupy octahedral (4f VI and 12k) and tetrahedral (4f IV ) positions (SG = P6 3 /mmc (No. 194)). The average particle size is 837–650 nm. Curie tempearature ( T C ) of the compounds monotonically decreased down to ∼520 K with increasing x . A frustrated magnetic state was detected from ZFC and FC magnetizations. saturation magnetization ( M s ) and effective magnetocrystalline anisotropy coefficient ( k eff ) were determined using the law of approach to saturation. A real permittivity ( ε / ) maximum of ∼3.3 at ∼45.5 GHz and an imaginary permittivity ( ε // ) of ∼1.6 at ∼42.3 GHz were observed for x = 0.1. A real permeability ( μ / ) maximum of ∼1.5 at ∼36.2 GHz was observed for x = 0. A μ // imaginary permeability maximum of ∼0.8 at ∼38.3 GHz was observed for x = 0.1. The interpretation of the results is based on the type of dielectric polarization and the natural ferromagnetic resonance features.