Magnetic and structural analysis of BaZnxZrxFe12–2xO19 (x = 0.1–0.7) hexaferrite samples for magnetic applications

Abstract

Polycrystalline samples of M-type hexaferrite with BaZnxZrxFe12–2xO19 (x = 0.1–0.7) as chemical composition were synthesized successfully using solid state reaction technique. The structural, microstructural and magnetic properties of these samples were investigated. Rietveld analysis (goodness-of-fit ≈1.06–1.22) demonstrates the phase purity of the samples in the entire composition range. The `c/a′ ratio is < 3.98, for all samples implying that they are M-type hexaferrites. The XRD results also show a simultaneous decrease in crystallite size (149–69 nm) and an increase in cell volume (699.119–711.006 Å3) with increasing dopant concentration. FESEM micrographs reveal that the a) average grain size varies within 0.61–0.79 µm and b) sample porosity decreases with increasing concentration of Zn2+- Zr4+ dopants. EDX data reveals the presence of all the elements and Ba:Fe ratio ≈ 1:12. M-H studies reveal that a) Ms increases from 61.45 emu/g (at x = 0) to 72.87 emu/g (at x = 0.1) and decreases afterwards to 61.45 emu/g (at x = 0.7) and b) Hc decreases continuously from 4118 Oe (at x = 0.0) to 319 Oe (at x = 0.7). The excellent magnetic properties of these hexaferrite samples make them useful in magnetic data storage devices, devices for microwave absorption and in spintronic devices.