磁控溅射制备BiFeO_3/Sr_(1-x)La_xFe_(12-x)Co_xO_(19)复合薄膜及其磁性能研究

Preparation of BiFeO_3/Sr_(1-x)La_xFe_(12-x)Co_xO_(19) Composite Films by Magnetron Sputtering and Their Magnetic Properties

室温下采用射频磁控溅射法,在P型<100>Si基衬底上分别制备了BiFeO_3(BFO)和Sr_(1-x)La_xFe_(12-x)Co_xO_(19)(x=0~0.3)的单层及2-2型BiFeO_3/Sr_(1-x)La_xFe_(12-x)Co_xO_(19)叠层式复合结构薄膜。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和材料综合物性测试系统(PPMS)对薄膜样品的微观结构、表面形貌以及磁学性能进行了测试分析。结果表明,随着x的增加,Sr_(1-x)La_xFe_(12-x)Co_xO_(19)单层膜的矫顽力先少量减小后增加,剩磁比起初不变然后递增,而剩余磁化强度一直减小。当x=0.3时,其矫顽力和剩磁比均达到最大值,分别为491 kA/m和0.69,而剩余磁化强度达到最小值为50(A·m^2)/kg;复合薄膜的矫顽力及剩磁比先增加后减小,剩余磁化强度一直减小,在x=0.2矫顽力和剩磁比均达到最大值,分别为425 kA/m和0.73,当x=0.3时矫顽力和剩磁比明显减弱,分别为171 kA/m和0.4,此时剩余磁化强度为最小值19(A·m^2)/kg。

BiFeO3（BFO） and Sr1-xLaxFe12-xCoxO19（x=0～0.3） monolayer films and 2-2 BiFeO3/Sr1-xLaxFe12-xCoxO19 stacked composite films were prepared on the P-type 100 Si-based substrates by magnetron sputtering at room temperature.The microstructure,surface morphology and magnetic properties of thin film samples were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and a comprehensive test system（PPMS） of material properties,respectively.The results indicate that with the increase of x,the coercive force of Sr1-xLaxFe12-xCoxO19 monolayer increases after small decrease,residual magnetism ratio does not change at first and then increases,while the residual magnetization is always reduced.When x = 0.3 the coercive force and the residual magnetism ratio reach the maximum value of 491 kA/m and 0.69,respectively,and the residual magnetization reaches the minimum value of 50（A·m^2）/kg.The coercive force and residual magnetism ratio of the composite film decrease after the first increase,while the residual magnetization is reduced.At x = 0.2 the coercive force and residual magnetism ratio reach a maximum value of 425 kA/m and 0.73,respectively.When x =0.3 the coercive force and the residual magnetism ratio decrease significantly to 171 kA/m and 0.4,respectively,and the residual magnetization in this case is the minimum value of 19（A·m^2）/kg.