Effect of Pt underlayer on the coercivity of FePt sputtered film

详细信息	查看全文 | 推荐本文 |

• 作者：C.W. Hsu ; S.K. Chen ; W.M. Liao ; F.T. Yuan ; W.C. Chang ; J.L. Tsai
• 关键词：FePt ; Thin film ; Pt underlayer ; Thermal expansion coefficient ; Residual stress
• 刊名：Journal of Alloys and Compounds
• 出版年：2008
• 期刊代码：45_09258388
• 类别：ms
• 出版时间：31 January 2008
• 卷：449
• 期：1-2
• 页码：52-55
• 文件大小：265 K

摘要

Magnetic properties of the FePt/Pt bilayers with Pt underlayer were investigated. By introducing the Pt underlayer, coercivity H_c and ordering parameter K of the film were enhanced by about of 50%. After a low-temperature annealing process at only 400 °C, H_c was increased from 6.26 to 9.78 kOe and K was increased from 0.586 to 0.844. Theoretical calculations indicated that there existed a compressive stress in the FePt film. The stress was found to release with the increase in thickness of the Pt underlayer. The increase in lattice parameter a_FePt and the decrease in lattice parameter c_FePt were closely related to the relaxed compressive stress in the FePt film as the thickness of Pt underlayer was increased. The relaxed compressive stress can account for the enhancement in the ordering parameter and the coercivity of the FePt/Pt bilayer materials.