压力对纳米CoFe_2O_4/SiO_2复合材料结构的影响

Effects of Pressure on the Structure of CoFe_2O_4/SiO_2 Nanocomposites

采用溶胶-凝胶工艺和高温高压实验技术,制备了纳米CoFe2O4/SiO2复合材料。利用X射线衍射仪、扫描电子显微镜和振动样品磁强计,对样品的结构、微观形貌和磁性进行了研究,并对CoFe2O4中阳离子的占位情况进行了讨论。结果表明,随着处理压力的升高,样品的晶粒尺寸增大,晶格常数减小,比饱和磁化强度增大。通过计算结果可以推断,压力的升高导致CoFe2O4中的部分Fe3+从A位移向了B位,而部分Co2+则从B位移向了A位。

Combined with sol-gel technology and high-pressure and high-temperature technique, CoFe2 04/SiO2 nanocomposites are fabricated. The structure and magnetic property of the nanocompos- ires are monitored by X-ray diffraction （XRD）, scanning electron microscope （SEM） and vibrating sample magnetometer （VSM）. The results show that the lattice constant of CoFe204 decreases but the grain size increases with im ration magnetization increa, tion results,it can be concl sites to B sites and the Co2 re in the experiment. Moreover, the specific satu mg treatment p pressure leads es to A sites. re to ssure. According to the calcula- the Fe3＋ ions transfer from A