Highly uniform submicrometre size particles of hexagonal strontium ferrite (SrFe12O19) have been synthesized by chemical coprecipitation technique at pH ⋍ 13. Chemical coprecipitation technique has helped in bringing down the ferritization temperature from 1300 to 925° C which is revealed by DTA-TG and XRD studies. Reproducible uniform single domain particle size and its distribution has been observed by scanning electron microscopy. X-ray and Mossbauer studies have identified single phase ferrite with Fe3+ ions occupying the proper crystallographic sites. The performance parameters of the sintered isotropic strontium ferrite magnets have proved to be superior by about 20% over the ferrites prepared by conventional ceramic technique.

Synthesis of chemically coprecipitated hexagonal strontium-ferrite and its characterization

Magnetic properties of strontium ferrite powder made by hydrothermal processing

The characteristics of Ni-Zn ferrite powder prepared by the hydrothermal process

Barium hexaferrite (BaFe{sub 12}O{sub 19}) particles have been prepared by the decomposition of an organometallic salt The properties of the ferrite particles have been investigated by x-ray diffractometry, Moessbauer spectroscopy, scanning electron microscopy, and magnetic measurements The size of the particles produced lie between 01 and 05 {mu}m To form the hexaferrite the decomposition product must be heated to > 620{degree}C Typical values of the saturation magnetization, coercivity, and remanence ratio of the hexaferrite particles are 333 kA{center dot}m{sup {minus}1} (63 emu/g{sup {minus}1}), 320 kA{center dot}m{sup {minus}1} (4 kOe), and 049, respectively

Preparation and characterization of barium hexaferrite powders produced by decomposition of organometallic complexes

A modified route for synthesizing barium hexaferrite (BaO.6Fe2O3) through ammonium carbonate using metal chlorides is reported. The coprecipitations were studied in the range of pH 7.2–8, Fe/Ba ratio 8.55–11.5, and dilutions of 0.005M–0.5M. The average particle size of these coprecipitates ranged from 20 A to 170 A. Ferritization studies have been carried out between 850° and 1150°C. The optimum specific magnetic moments and coercive fields were in the range of 49–53 emu/gm and 3.45–3.55 K Oe respectively.

N. K. Ghosh

Papers

Preparation, Characterization and Magnetic Property of Coprecipitated Barium Hexaferrite Powders