The role of Sn and Zn substitutions on the magnetic properties of nanosized Y-type hexaferrite prepared by sol-gel auto-combustion method

The current paper has focused on the improvement of the magnetic performance of the Sn, Zn-doped Y-type hexaferrite nanoparticles via the sol-gel auto-combustion method. The partial replacement of nonmagnetic Zn2+ and Sn4+ cations for the magnetic Fe3+ cation was studied. At the low Zn-Sn concentration, the Sn4+ cations had a preference for octahedral locations (12k, 2a, 4f2) and the Zn2+ cations had a strong tendency to move to the tetrahedral spaces (4f1), respectively. Based on this data, the single-phase hexaferrites with the chemical formula of Sr2Co1.7Mg0.3Fe(12-x)Snx/2Znx/2O22 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were successfully synthesized via the sol-gel auto-combustion method. The x-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Field Emission Scanning Electron Microscopy (FESEM) and Vibrating Sample Magnetometer (VSM) were carried out to investigate the obtained ferrite performance. The results revealed the formation of the single-phase platelet-like Y-type hexagonal ferrites after calcinations at 1000 degrees C with a thickness of 30-70 nm and a particle size of 90-210 nm. The obtained nanosized ferrites had the magnetic coercivity (Hc) and the saturation magnetization (Ms) in the range of 2100-637 Oe and 38-48 emu g-1, respectively. The addition of Sn, Zn dopants enhanced the saturation magnetization and reduced the magnetic coercivity, which can make this ferrite a candidate for some applications.