Synthesis and Characterization of Cu–Mn Substituted SrFe12O19 Hexaferrites

In this study, bimetallic (Cu-Mn) substituted SrFe12O19 hexaferrites [Sr1-2xMnxCuxFe12O19 (0.0 <= x <= 0.1)] were synthesized via sol-gel auto-combustion approach. The effect of bimetallic substitution on structure, morphology and magnetism of SrFe12O19 was investigated. SEM images divulge the nano-size of the prepared products with speck morphology. X-ray powder diffraction analysis affirmed their complete conversion to SrFe12O19 hexagonal crystal phase. The results from Fe-57 Mossbauer suggested that all five important sextets of Sr1-2xMnxCuxFe12O19 hexaferrites effected due to the substitution of Cu and Mn ions. Cation distribution calculation showed that as the percentage of Mn and Cu increased in Sr1-2xMnxCuxFe12O19 (0.0 <= x <= 0.1), particularly for x = 0.03 the relative area of 12k and 4f(2) site increased. This indicates that Fe ions are migrated towards 12k and 4f(2) octahedral site

Synthesis and Structural and Magnetic Characterization of BaZn x Fe12−x O19 Hexaferrite: Hyperfine Interactions

To study the effect of Zn substitution on structural magnetic properties and hyperfine interactions of barium hexaferrite, BaFe12-x Zn (x) O-19 (0.0aexae0.3) hexaferrites were synthesized via sol-gel auto-combustion technique. Rietveld analysis of XRD powder patterns confirmed the formation of single-phase hexaferrites for all products. Due to the larger ionic size of Zn2+ as compared with Fe3+, while x increases, the lattice constant parameters increase to a small degree. Nanoplate morphology of the products is presented by SEM analyses. It was observed that both saturation magnetization and coercivity decrease in almost the same manner with zinc concentration for all substitutions. Cation distribution calculations showed that Zn2+ occupies 12k, 4 f (2), 4 f (1), and 2b sites and at the same time pushes Fe3+ ions towards 2a and 12 k (1) sites. From(57)Fe Mossbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values on Zn2+ substitution have been determined