Structural properties and hyperfine interactions in Co–Zn Y-type hexaferrites prepared by sol–gel method

Abstract Y-type barium hexaferrites Ba 2 Co 2− x Zn x Fe 12 O 22 (0.0≤ x ≤2.0) were prepared using sol–gel method and then sintering at temperatures between 900 and 1100 °C. The properties of the prepared samples were investigated using X-ray diffraction, scanning electron microscopy, and Mossbauer spectroscopy. XRD patterns revealed the presence of a single Y-type hexaferrite phase in the samples sintered at temperatures above 1000 °C. Mossbauer data indicated that Co 2+ ions occupied octahedral sites in the T blocks, while Zn 2+ ions were distributed between the two tetrahedral sites. This trend for cationic distribution resulted in weakening the superexchange interactions between spin-up and spin-down sublattices with increasing Zn content, and a consequent reduction in the hyperfine fields in Zn rich compounds.