热处理温度对Co_(0.8)Fe_(2.2)O_4/SiO_2纳米复合薄膜结构和磁性能的影响

Effect of Annealing Temperature on the Structure and Magnetic Properties of Co_(0.8)Fe_(2.2)O_4/SiO_2 Nanocomposite Films

采用溶胶-凝胶旋涂法在经表面氧化的Si(100)基片上制备了Co0.8Fe2.2O4/Si O2纳米复合薄膜。利用X射线衍射仪、扫描电子显微镜和振动样品磁强计对Co0.8Fe2.2O4/Si O2纳米复合薄膜的结构、形貌和磁性能进行分析,研究了热处理温度对复合薄膜结构和磁性能的影响。结果表明:热处理温度高于750℃时复合薄膜中Co0.8Fe2.2O4呈现尖晶石结构;当热处理温度从750℃升高到1 100℃,复合薄膜中Co0.8Fe2.2O4的晶粒尺寸从6 nm增大到34 nm,晶胞常数从0.836 9 nm增大到0.839 5 nm。样品的矫顽力随热处理温度的升高先增大后减小,经1 000℃热处理样品的矫顽力达到298.3 k A/m。

Co0.8Fe2.2O4/Si O2 nanocomposite films on Si（100） substrates were prepared by a sol-gel spin-coating technique. The effect of annealing temperature on the structure, morphology and magnetic properties of the nanocomposite films was investigated by X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry, respectively. The results show that Co0.8Fe2.2O4 in nanocomposite films annealed at 750 ℃ exhibits a cubic spinel structure. The grain size and the lattice constant of Co0.8Fe2.2O4 of the nanocomposite films increase from 6 nm to 34 nm and from 0.836 9 nm to 0.839 5 nm as the annealing temperature increases from 750 ℃ to 1 100 ℃, respectively. The coercivity of Co0.8Fe2.2O4/Si O2 nanocomposite films firstly increases and then decreases with the increase of the annealing temperature, and the higher coercivity of the film annealed at 1 000 ℃ is 298.3 k A/m.