Self-Combustion Synthesis of Co–Zr-doped Ba-Hexaferrite Nanoparticles and Their Studied Physicochemical and Magnetic Properties

Abstract

In our efforts to investigate the correlation between distributions of cations over five crystallographic positions, magnetic properties of Ba-hexaferrites (BaM) in the coupled substitution of magnetic Co2+ and nonmagnetic Zr4+ for Fe3+ were examined. During the present research, we have synthesized a series of BaCo x Zr x Fe(12−2x)O19 (x = 0.0−1.0) ferrites by self-combustion technique using urea as a fuel at a temperature of 950 ∘C. M-type hexagonal ferrites with some α–Fe2O3 phase have been confirmed by powder X-ray diffraction, and the average size of hexagonal platelets was 64 nm which was comparable with transmission electron microscopy (TEM). Metal oxide peaks in the region of 600–400 cm−1 in Fourier transform infrared spectroscopy (FT-IR) spectra confirm the structure coincidence with X-ray diffraction (XRD) results. The Brunauer–Emmett–Teller (BET) surface area (9.72 m2/g) and mesopore diameter (22.55 nm) of samples have been observed by using the Barrett–Joyner–Halenda (BJH) method. Mossbauer studies suggest that dopant ions largely preferred 4 f 2 sites up to x = 0.6 while substitution at 4 f 1 and 12k sites were indicated at higher concentrations. Magnetization measurements showed that the coercive force was steeply reduced from 4348 to 696 Oe with increasing Co–Zr contents but net magnetization was nearly constant (M S = 52.34−57.47 emu/g). High M S and low H C values of our materials make them particularly suitable for many electrical devices.