压力对纳米CoFe2O4/SiO2复合材料结构的影响

 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。

Effects of Pressure on the Structure of CoFe2O4/SiO2 Nanocomposites

Combined with sol-gel technology and high-pressure and high-temperature technique, CoFe₂O₄/SiO₂ nanocomposites are fabricated. The structure and magnetic property of the nanocomposites are monitored by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results show that the lattice constant of CoFe₂O₄ decreases but the grain size increases with increasing treatment pressure in the experiment. Moreover, the specific saturation magnetization increases gradually with increasing treatment pressure. According to the calculation results, it can be concluded that the increasing pressure leads to the Fe³⁺ ions transfer from A sites to B sites and the Co²⁺ ions transfer from B sites to A sites.