Thermal Decay and Reversal of Exchange Bias Field of CoFe/PtMn Bilayer after Ga+ Irradiation
ZHOU Guang-Hong1,2**, ZHU Yu-Fu1, LIN Yue-Bin1
1Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 2Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
Thermal Decay and Reversal of Exchange Bias Field of CoFe/PtMn Bilayer after Ga+ Irradiation
ZHOU Guang-Hong1,2**, ZHU Yu-Fu1, LIN Yue-Bin1
1Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 2Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
摘要An applied field is used to perform Ga+ ion irradiation on a CoFe/PtMn bilayer. Effects of the applied field and energy transfer between Ga+ ions and antiferromagnetic (AFM) atoms on the exchange bias field H ex are investigated. A partially reversed Hex is found in CoFe/PtMn specimens irradiated at a dose of 1×1014 ions/cm2 with an applied field anti−parallel to the original exchange bias direction. We believe that the rapid energy transfer and local temperature increase originating from the interaction between Ga+ ions and AFM atoms result in spin reversal and the formation of reversed AFM domains when specimens are irradiated with anti−parallel fields. The decrease in H ex when annealing the film in a negative saturation field indicates a thermal decay process. The AFM moments are reversed by thermal activation over an energy barrier distribution, which may change in some way as the temperature increases.
Abstract：An applied field is used to perform Ga+ ion irradiation on a CoFe/PtMn bilayer. Effects of the applied field and energy transfer between Ga+ ions and antiferromagnetic (AFM) atoms on the exchange bias field H ex are investigated. A partially reversed Hex is found in CoFe/PtMn specimens irradiated at a dose of 1×1014 ions/cm2 with an applied field anti−parallel to the original exchange bias direction. We believe that the rapid energy transfer and local temperature increase originating from the interaction between Ga+ ions and AFM atoms result in spin reversal and the formation of reversed AFM domains when specimens are irradiated with anti−parallel fields. The decrease in H ex when annealing the film in a negative saturation field indicates a thermal decay process. The AFM moments are reversed by thermal activation over an energy barrier distribution, which may change in some way as the temperature increases.
ZHOU Guang-Hong;**;ZHU Yu-Fu;LIN Yue-Bin
. Thermal Decay and Reversal of Exchange Bias Field of CoFe/PtMn Bilayer after Ga+ Irradiation[J]. 中国物理快报, 2011, 28(5): 57502-057502.
ZHOU Guang-Hong, **, ZHU Yu-Fu, LIN Yue-Bin
. Thermal Decay and Reversal of Exchange Bias Field of CoFe/PtMn Bilayer after Ga+ Irradiation. Chin. Phys. Lett., 2011, 28(5): 57502-057502.
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2011, Vol. 28 
