厚度对磁控溅射CoPt永磁薄膜磁性能的影响

Effect of thickness on magnetic properties of magnetron sputtering CoPt permanent magnetic film

CoPt永磁薄膜有较高的剩磁和矫顽力,通常用作磁传感器中的磁偏置或者微机电系统(MEMS)中的磁制动部件。CoPt薄膜多采用磁控溅射或离子束沉积工艺制备。采用磁控溅射制备了不同厚度CoPt/Cr薄膜。结果显示,CoPt薄膜矫顽力随薄膜厚度增加而降低;薄膜较厚时(大于400?),剩磁随薄膜的厚度增加而降低。这主要是因为CoPt薄膜具有密集六方结构,其自然生长为(002)面,具有垂直各向异性。由于Cr缓冲层存在,CoPt薄膜较薄时沿(1010)面生长,从而具有面内各向异性;但随薄膜厚度的增加,薄膜会沿(002)生长从而具有垂直各向异性,导致薄膜磁性能降低。

CoPt thin films with different thickness were prepared by magnetron sputtering, and their magnetic properties were studied in this paper. The results show that the coercivity of thin films declines with film thickness increasing. Remnant magnetization increases with film thickness increasing for thickness of thinner than 400 ？ and declines with thickness increasing for thicker films. As the result showing, the CoPt film has the hcp structure and the nature grows plane is （002）,which has perpendicular magnetic anisotropy. The film grows along （1010 ） plane with Cr buffer layer. The sputtered CoPt grows along （1010 ） plane while the thickness is thin and along （002） plane as the thickness is thick, which decreases the magnetic properties.