中国物理B ›› 2014, Vol. 23 ›› Issue (10): 107502-107502.doi: 10.1088/1674-1056/23/10/107502

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Asymmetric exchange bias training effect in spin glass (FeAu)/FeNi bilayers

芮文彬a, 何茂诚a, 游彪a, 时钟b, 周仕明b, 肖明文a, 高远a, 张维a, 孙力c, 杜军a   

  1. a National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    b Department of Physics, Tongji University, Shanghai 200092, China;
    c Department of Mechanical Engineering and Texas Center for Superconductivity (TcSUH), University of Houston, Houston, TX 77204, USA
  • 收稿日期:2014-05-09 修回日期:2014-06-07 出版日期:2014-10-15 发布日期:2014-10-15
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant Nos. 2014CB921101 and 2010CB923401) and the National Natural Science Foundations of China (Grant Nos. 51331004, 11074112, and 11174131).

Asymmetric exchange bias training effect in spin glass (FeAu)/FeNi bilayers

Rui Wen-Bin (芮文彬)a, He Mao-Cheng (何茂诚)a, You Biao (游彪)a, Shi Zhong (时钟)b, Zhou Shi-Ming (周仕明)b, Xiao Ming-Wen (肖明文)a, Gao Yuan (高远)a, Zhang Wei (张维)a, Sun Li (孙力)c, Du Jun (杜军)a   

  1. a National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    b Department of Physics, Tongji University, Shanghai 200092, China;
    c Department of Mechanical Engineering and Texas Center for Superconductivity (TcSUH), University of Houston, Houston, TX 77204, USA
  • Received:2014-05-09 Revised:2014-06-07 Online:2014-10-15 Published:2014-10-15
  • Contact: Du Jun E-mail:jdu@nju.edu.cn
  • About author:75.70.Cn; 75.50.Lk; 75.60.-d
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant Nos. 2014CB921101 and 2010CB923401) and the National Natural Science Foundations of China (Grant Nos. 51331004, 11074112, and 11174131).

摘要: A significant exchange bias (EB) training effect has been observed in sputter deposited FeAu/FeNi bilayers, wherein the exchange field (HE) exhibits a special sign-changeable temperature dependence. Very interestingly, despite the absence of multiple easy axes in the FeAu spin glass (SG) layer, HE drops abruptly between the first and second magnetic cycles, which is followed by a more gradual continuous change in the subsequent cycles. This training behavior cannot be described by the empirical n-1/2 law because of the asymmetric magnetization reversal processes. We propose modifying Binek's model to include the asymmetric changes of the pinning SG spins at the descending and ascending branches. This new model successfully describes the EB training effect in FeAu/FeNi bilayers.

关键词: exchange bias, training effect, spin glass

Abstract: A significant exchange bias (EB) training effect has been observed in sputter deposited FeAu/FeNi bilayers, wherein the exchange field (HE) exhibits a special sign-changeable temperature dependence. Very interestingly, despite the absence of multiple easy axes in the FeAu spin glass (SG) layer, HE drops abruptly between the first and second magnetic cycles, which is followed by a more gradual continuous change in the subsequent cycles. This training behavior cannot be described by the empirical n-1/2 law because of the asymmetric magnetization reversal processes. We propose modifying Binek's model to include the asymmetric changes of the pinning SG spins at the descending and ascending branches. This new model successfully describes the EB training effect in FeAu/FeNi bilayers.

Key words: exchange bias, training effect, spin glass

中图分类号:  (Magnetic properties of interfaces (multilayers, superlattices, heterostructures))

  • 75.70.Cn
75.50.Lk (Spin glasses and other random magnets) 75.60.-d (Domain effects, magnetization curves, and hysteresis)