Laser-induced Magnetization Dynamics for Llo-FePt Thin Films with Perpendicular Anisotropy

摘要：

Laser-induced de- and re-magnetization dynamics in perpendicularly magnetized Llo-FePt films are studied by using a time-resolved magneto-optical pump-probe technique. The observed ultrafast magnetic dynamic behaviors depend on the film thickness and substrate temperature. The thinner FePt film has a relatively larger maximum demagnetization percentage and a slower relaxation rate because of fewer free electrons being in the laser spot area. However, for the same thickness samples, although they have the same maximum demagnetization, their magnetization recovery speed is different. The sample deposited at high Ts exhibits a faster recovery due to the relatively large FePt grains with high magnetocrystalline anisotropy energy. In addition, we find that all the FePt samples reach the maximum demagnetization at an almost same characteristic delay time of 0.9 picoseconds, irrespective of the laser intensity, film thickness, and substrate temperature.

关键词： Magnetization dynamics Perpendicular anisotropy Laser heating

作者: Boyin Cui Jiaqi Zhao Zongzhi Zhang B. Ma Q. Y. Jin

作者单位: Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education),Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China

会议类型: 国际会议

会议名称: The 7th International Symposium on Advanced Photonic and Technology(第七届光子先进科学与技术国际会议)

会议地点: 上海

会议语种:英文

页码: 1269-1273

在线出版日期: 2009-07-26（万方平台首次上网日期，不代表论文的发表时间）