Structural, magnetic and Mössbauer studies of Ba_0.5Sr_1.5Me₂Fe₁₂O₂₂ (where Me = Co, Zn and Ni) Y-type hexaferrites

The Y-type hexaferrites, Ba_0.5Sr_1.5Me₂Fe₁₂O₂₂ (where Me = Co, Zn and Ni), were synthesized by employing the solid-state technique. The prepared samples were examined using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray analysis (EDAX) spectrometer, X-ray photoelectron spectroscopy (XPS), magnetic and room temperature Mössbauer spectroscopy techniques. The information from the XRD confirms the rhombohedral structure with space group R-3m for the samples under study. The average crystallite size varies between 75 and 80 nm. The morphology of the samples by FESEM reveals that the grains are interconnective, homogeneously distributed and the average grain size varies from 2.2 to 3.1 µm. The nominal composition of all elements and their oxidation state was established with XPS and confirms that the Fe ions are in + 3 state. The measured room temperature magnetization properties inveterate the soft ferrimagnetic character of the samples. The enhanced saturation magnetization is noticed for Zn Y-type hexaferrites, i.e., 31 emu/g. The room temperature Mössbauer spectra confirm the existence of magnetic ordering in all the compounds. The Mössbauer spectra confirm the coevality of Fe ions at six sub-lattices with dissimilar occupancy ratio. The isomer shift values confirm the Fe ions in Fe³⁺ state.