Cooling field and temperature dependent exchange bias in spin glass/ferromagnet bilayers.
We report on the experimental and theoretical studies of cooling field (HFC) and temperature (T) dependent exchange bias (EB) in FexAu1-x/Fe19Ni81 spin glass (SG)/ferromagnet (FM) bilayers. When x varies from 8% to 14% in the FexAu1-x SG alloys, with increasing T, a sign-changeable exchange bias field (HE) together with a unimodal distribution of coercivity (HC) are observed. Significantly, increasing in the magnitude of HFC reduces (increases) the value of HE in the negative (positive) region, resulting in the entire HE∼T curve to move leftwards and upwards. In the meanwhile, HFC variation has weak effects on HC. By Monte Carlo simulation using a SG/FM vector model, we are able to reproduce such HE dependences on T and HFC for the SG/FM system. Thus this work reveals that the SG/FM bilayer system containing intimately coupled interface, instead of a single SG layer, is responsible for the novel EB properties.
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
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Rui
College of Sciences, Northeastern University, Shenyang, 110819, P. R. China.|MOE Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang, 110819, P. R. China.
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Hu
College of Sciences, Northeastern University, Shenyang, 110819, P. R. China.
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Du
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, P. R. China.
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You
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
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Xiao
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
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Zhang
Department of Physics, Tongji University, Shanghai, 200092, P. R. China.
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Zhou
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, P. R. China.
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