Method for preparation of magnetic spinel ferrites from layered double hydroxide precursors

摘要

The invention describes a method of preparing magnetic ferrites from layered precursors in which Fe²⁺ is first introduced into the layers of layered double hydroxides (LDHs) in order to prepare Me-Fe²⁺-Fe³⁺ LDHs, and then by utilizing the easily oxidized nature of Fe²⁺, binary or multi-component ferrite materials containing Fe³⁺ in a single crystalline phase can be prepared. Values of the saturation magnetization of ferrites prepared by the method are significantly increased compared with ferrites prepared by traditional methods. Because the metal elements in the layered precursor have the characteristics of a high degree of dispersion, high activity and small particle size (average particle size 40-200 nm), no milling is required before calcination, thus simplifying the production process, shortening the production period, reducing capital investment in equipment and economizing on energy costs. In addition, the method does not corrode production equipment and does not pollute the environment.