Effects of sputtering argon pressure on the exchange coupling field for NiFe/IrMn

• Main Authors: Po-Chung Cheng, 鄭博仲
• Other Authors: 洪連輝
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/24678530703104551527

碩士 === 國立彰化師範大學 === 光電科技研究所 === 98 === We have investigated the effects of sputtering argon pressure on the exchange coupling field for NiFe/IrMn bilayers. In this study, ferromagnetic NiFe layer and antiferromagnetic IrMn layer were deposited at different pressures respectively. The ferromagnet /antiferromagnet exchange coupling strength was found to be closely related to the pressure. To understand the effect of pressure on microstructures, x-ray diffraction (XRD) and atomic force microscopy (AFM) measurements were used to investigate a correlation of the crystalline texture and interface topography with observed magnetic properties. The interface topography and crystalline structure of nano-thin films are dependent on sputtering pressure. Low argon pressure results in a smooth surface, and the XRD peak intensity of NiFe (111) and IrMn (111) decrease with higher pressure. The exchange bias field increase with increasing NiFe layers sputtering pressure from 2 to 7 mTorr and then decrease from 7 to 10 mTorr. The decreasing of exchange bias is a result from the competition between interface roughness and texture effects. By systematic analysis, we could know more detailed microscopic descriptions of the mechanism of exchange coupling.