Investigation of Magnetic Properties of Barium Ferrite Powders by Remanence Curves

Abstract

Barium ferrite powders prepared by the glass crystallization method are investigated with help of remanence curves. In evaluating the experiments the influence of thermal fluctuations is separated to obtain the intrinsic anisotropy field distribution. In particular, the temperature dependence of the mean anisotropy field and the coercivity (Hc) is determined. The influence of the anisotropy field distribution on Hc is demonstrated and discussed in comparison with experiment. The unusual dependence of the coercivity on the flake treatment temperature is analysed and clarified using remanence curves. The influence of particle–particle interaction effects is shown and discussed in connection with the microstructure of the particle assembly.

Fabrication and magnetic properties of Fe3O4 nanowire arrays in different diameters

“…The exponent k has a value of k ¼ 0.5 for an assembly of aligned particles and k ¼ 0.77 for randomly orientation particles [34,35]. Our experimental results cannot be fitted well by these two models, that is, the coercivities have non-linear relationship with T 0.5 or T 0.77 .…”

“…5b. Generally, the thermal dependence of coercivity for single domain particles is expected to follow the relationship [34,35] …”

Structural and magnetic properties of BaFe12−2xTixRuxO19

“…6 shows the reduced IRM curve and the corresponding switching field distribution for the samples with x = 0.0 and 0.3. The effective magnetic anisotropy field for each sample examined in this work is obtained from the maximum of the switching field distribution [39]:…”

Static magnetic properties of nanocrystalline Co-Ti doped barium ferrite BaFe/sub 12-2x/Co/sub x/Ti/sub x/O/sub 19/ (x=0.8)

“…We note that the width of the anisotropy field distribution g(H,) strongly increases as we go down in temperature, and we assume that this is due to the fact that g(H,) cannot be calculated correctly in the high-field region at low temperatures since we cannot rotate the magnetic moments of all blocked particles. Pfeiffer et al 131 proposed that the intrinsic mean value of the anisotropy field <H,(T)> may be obtained by removing thermal fluctuations through <H,(T)> =z.<H,(T)>, being z the solution of the-quation …”