Multiferroic properties and Mössbauer Study of M-type hexaferrite PbFe12O19 synthesized by the high energy ball milling

Abstract M-type hexaferrite PbFe12O19 nano-crystallites with an average diameter of 68 nm are synthesized by high energy ball milling method. The Rietveld refinement of the X-ray diffraction (XRD) pattern has confirmed the single-phase magnetoplumbite (M) structure of the sample with the space group P63/mmc. Surface morphology is analyzed using transmission and field emission scanning electron microscopes (TEM and FE-SEM). Dielectric studies revealed ferro- to antiferro- and antiferro- to paraelectric transitions. Initial permeability is found to be invariant with temperature and frequency. Small polaron hopping is found to be the prominent conduction mechanism. The room temperature Mossbauer spectrum showed a superposition of five sextets (Zeeman splitting patterns) associated with the five sites of the iron ions, which are ferric (Fe3+) state. The values of the hyperfine magnetic fields are found to be 51.12, 50.8, 48.95, 41.15, and 40.11 Tesla corresponding to the 4f2↓, 2a↑, 4f1↓, 12 k↑, and 2b↑ sites, respectively.