Mechanism of Phase Transformation and Formation of Barium Hexaferrite Doped with Rare-Earths in Sol-Gel Process

摘要

The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La~(3+) were studied by chemical phase analysis, X-ray diffraction and infrared spectrometry analysis. The experimental results show that phase transformation reactions of FeCO_3, Fe_2O_3 and BaFe_2O_4, barium hexaferrite and γ-Fe_2O_3 take place in the heal treatment of gel. While the doping lanthanide ion replace barium ion, an equivalent quantity of Fe~(3+) are reduced to Fe~(2+) to maintain the charge equilibrium.