Time-Resolved Magneto-Optical Kerr Effect of Magnetic Thin Films for Ultrafast Thermal Characterization.
Thermomagnetic and magneto-optical effects are two fundamental but unique phenomena existing in magnetic materials. In this work, we demonstrate ultrafast time-resolved magneto-optical Kerr effect (TR-MOKE) as an advanced thermal characterization technique by studying the original factors of the MOKE signal from four magnetic transducers, including TbFe, GdFeCo, Co/Pd, and CoFe/Pt. A figure of merit is proposed to evaluate the performance of the transducer layers, corresponding to the degree of the signal-to-noise ratio in TR-MOKE measurements. We observe improved figure of merit for rare-earth transition-metal-based TbFe and GdFeCo transducers and attribute this improvement to their relatively larger temperature-dependent magnetization and the Kerr rotation angle at the saturated magnetization state. Furthermore, an optimal thickness of TbFe is found to be ∼18.5 nm to give the best performance. Our findings will facilitate the nanoscale thermal characterization and the device design where the thermo-magneto-optical coupling plays an important role.
Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Jun-Yang
JY
Chen
Department of Mechanical Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.|Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing 100190, China.
Jie
J
Zhu
Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Delin
D
Zhang
Department of Mechanical Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Dustin M
DM
Lattery
Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Mo
M
Li
Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Jian-Ping
JP
Wang
Department of Mechanical Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Xiaojia
X
Wang