掺杂Mg对纳米CoFe_2O_4/SiO_2复合薄膜结构和磁性的影响  

Effect of Mg-doping on the structural and magnetic properties of CoFe_2O_4/SiO_2 nanocomposite films

作　　者：刘宇[1] 李季[1] 张玉梅[1] 华杰[1] 刘梅[1] 李海波[1] 

机构地区：[1]吉林师范大学功能材料物理与化学教育部重点实验室,四平136000

出　　处：《复合材料学报》2012年第2期98-102,共5页Acta Materiae Compositae Sinica

基　　金：吉林省科技发展计划资助项目(20090144)

摘　　要：采用溶胶-凝胶旋涂法制备了纳米Co1-xMgxFe2O4/SiO2(x=0,0.2,0.4,0.6,0.8)复合薄膜。利用XRD、SEM、原子力显微镜、振动样品磁强计对薄膜的结构、形貌和磁性进行了分析,研究了Mg2+含量对样品结构和磁性的影响。结果表明,样品中Co1-xMgxFe2O4具有尖晶石结构,晶粒尺寸在38～46nm之间。随着Mg2+含量的增加,Co1-xMgxFe2O4的晶格常数减小,样品的饱和磁化强度减小,矫顽力先增大后减小。样品Co0.4Mg0.6Fe2O4/SiO2垂直和平行膜面的矫顽力分别为350.7kA.m-1和279.4kA.m-1,剩磁比分别为67.2%和53.9%,Co1-xMgxFe2O4/SiO2复合薄膜具有较明显的垂直磁各向异性。Co1-xMgxFe2O4/SiO2（x=0,0.2,0.4,0.6,0.8） nanocomposite films were prepared by the sol-gel spin-coating process.The effect of the addition of Mg2＋ with various content on the structure and magnetic properties of the samples was investigated.The structure,morphology and magnetic properties of the films had been studied through XRD,SEM,atomic force microscopy（AFM） and vibrating sample magnetometer（VSM）.The results show that the Co1-xMgxFe2O4 presents spinel structure in composite films with the grain size of about 38~46 nm.As the content of Mg increases,the lattice constant of Co1-xMgxFe2O4 decreases,the saturation magnetization of sample films also decreases,while the coercivity first increases and then decreases.The value of coercivity and remanence ratio in the direction of parallel to the plane for Co0.4Mg0.6Fe2O4/SiO2 sample film is 279.4 kA·m-1 and 53.9%,respectively,while the corresponding value in the direction of perpendicular to the plane is 350.7 kA·m-1 and 67.2%.The Co1-xMgxFe2O4/SiO2 nanocomposite films display distinct perpendicular magnetic anisotropy.

关 键 词：铁氧体薄膜 纳米复合材料 结构 磁性 掺杂 

分 类 号：TB332[一般工业技术—材料科学与工程] O482.5[理学—固体物理]