Preparation and characterization of spinel-type MeF2O4 fibres
1. School of Material Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Mechanical and Elec trical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016, China)
Abstract:The spinel-type MeF2O4 ( Me = Co, Ni, Zn) fibres have been successfully prepared by the organic gel thermal decomposition process from raw materials of metal salts and citric acid. The gel precursors and the resultant fibres derived from thermal decomposition of these precursors were characterized by FTIR, DSC, XRD, SEM, and VSM. The results show that linear-type structural molecules for the gel precursors are possibly formed by means of single dentate liganding type among citric acid and metal ions during the complexation reaction, and the gel composed of these linear-type molecules exhibits a good spinning performance. The smooth and compact spinel ferrite fibres consisted of several decade nanometer crystallites are obtained by proper thermal treatment process. The smallest diameters of fibres can be less than 1 μm, and the aspect ratios(length/diameter) up to 106. The MeFe2O4( Me = Co, Ni, Zn) ferrite fibres have good magnetic properties at room temperature, and the specific saturation magnetization of these fen'ite fibres decreases in the sequence of Co, Ni, and Zn. The shape anisotropy of fibres shows influence on its magnetic properties.