Effects of calcination temperature and solution pH value on the structural and magnetic properties of Ba 2Co 2Fe 12O 22 ferrite via EDTA-complexing process

Abstract

Y-type hexagonal Ba 2Co 2Fe 12O 22 was prepared via a simple EDTA-complexing process using corresponding metal nitrates as raw materials and ethylene diamine tetraacetic acid (EDTA) as complexing agent. The decomposition process of the precursor, formation process of Ba 2Co 2Fe 12O 22, structure, morphology and magnetic properties of the particles were investigated by thermogravimetric analysis and differential thermal analysis (TGA–DTA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The effects of calcination temperature and solution pH value on the structure and magnetic properties of the particles were studied. The results showed that the formation of single phase Ba 2Co 2Fe 12O 22 was achieved by controlling the calcination temperature ≥1000 °C. Meanwhile, the pH value ≥8 of initial solution was necessary to form stable metal–EDTA complexes and to produce high quality Ba 2Co 2Fe 12O 22. The magnetic properties showed dependence on the preparation conditions and microstructures. Saturation magnetization ( M s) and coercivity ( H c) were obtained in the range of 30.2–44.8 emu g −1 and 91.7–1953.7 Oe for samples calcined from 700 to 1200 °C, and 28.8–33.4 emu g −1 and 190.1–84.0 Oe for samples from initial solution of pH 3.8–10.1.