中国物理B ›› 2003, Vol. 12 ›› Issue (6): 665-668.doi: 10.1088/1009-1963/12/6/317

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Bulk-like contribution to tunnel magnetoresistance in magnetic tunnel junctions

沈峰1, 张泽1, X. H. Xiang2, G. Landry2, John Q. Xiao2, 詹文山3, 朱涛4   

  1. (1)Beijing Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; (2)Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA; (3)State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; (4)State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; Department of Physics and Astronomy, University of Delaware,
  • 收稿日期:2003-01-08 修回日期:2003-01-27 出版日期:2003-06-16 发布日期:2005-03-16
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 50171078).

Bulk-like contribution to tunnel magnetoresistance in magnetic tunnel junctions

Zhu Tao (朱涛)ab, Zhan Wen-Shan (詹文山)a, Shen Feng (沈峰)c, Zhang Ze (张泽)c, X. H. Xiangb, G. Landryb, John Q. Xiaob   

  1. a State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; b Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA; c Beijing Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Received:2003-01-08 Revised:2003-01-27 Online:2003-06-16 Published:2005-03-16
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 50171078).

摘要: We have demonstrated that the bulk-like contribution to tunnelling magnetoresistance (TMR) exists in the magnetic tunnel junctions, and is determined by the tunnelling characteristic length of the ferromagnetic electrodes. In the experiment, a wedge-shaped CoFe layer is inserted at the interface between the insulating barrier and the reference electrode. It is found that TMR ratio increases from 18% without CoFe layer to a saturation value of 26.5% when the CoFe thickness is about 2.3 nm. The tunnelling characteristic length, l_{tc}, can be obtained to be about 0.8 nm for CoFe materials.

Abstract: We have demonstrated that the bulk-like contribution to tunnelling magnetoresistance (TMR) exists in the magnetic tunnel junctions, and is determined by the tunnelling characteristic length of the ferromagnetic electrodes. In the experiment, a wedge-shaped CoFe layer is inserted at the interface between the insulating barrier and the reference electrode. It is found that TMR ratio increases from 18% without CoFe layer to a saturation value of 26.5% when the CoFe thickness is about 2.3 nm. The tunnelling characteristic length, $l_{\rm tc}$, can be obtained to be about 0.8 nm for CoFe materials.

Key words: tunnelling magnetoresistance, magnetic tunnel junctions

中图分类号:  (Other materials)

  • 75.47.Pq
75.70.Cn (Magnetic properties of interfaces (multilayers, superlattices, heterostructures))