Investigation of Magnetic Properties of Zn Doped Y-Type Barium Ferrite

The Ba₂Co_2-xZn_xFe₁₂O₂₂ (x = 0.0$, 0.5, 1.0, 1.5, and 2.0) polycrystalline samples were synthesized by the solid-state reaction method. Based on the Rietveld refinement, the crystal structures of samples were found to be single-phased and determined to be rhombohedral with space group of R - 3m. The unit cell volume (V_u) of the samples increased with increasing Zn ion concentration. In the magnetic phase diagram of Ba₂Co_2-xZn_xFe₁₂O₂₂ system, samples with x ≤ 1.5 showed the spin transitions both at T_s and T_C. For x = 2.0 sample, we observed the disappearance T_s. The non-magnetic Zn ions preferentially occupy the tetrahedral sublattices of 6c_IV*, and 6c_IV* with down-spin site. At low temperature, this leads to the increase in M_s. However, the experimentally measured M_s at 295 K shows a slight decrease around x = 1.5. In - ddition, we have measured Mössbauer spectra of samples at various temperatures ranging from 4.2 to 750 K, which can analyzed with six-sextets for Fe sites corresponding to the 3b_VI, 6c_IV*, 6c_VI, 18h_VI, 6c_IV, and 3α_VI of the Y-type hexagonal crystallographic sites. From the Mössbauer spectra of 295 K, we observed the line-width broadening with increasing Zn concentration.