中国物理B ›› 2013, Vol. 22 ›› Issue (5): 57503-057503.doi: 10.1088/1674-1056/22/5/057503

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

Oscillation of coercivity between positive and negative in MnxGe1-x:H ferromagnetic semiconductor films

秦羽丰a b, 颜世申a, 萧淑琴a, 李强a, 代正坤a, 沈婷婷a, 杨爱春a, 裴娟a, 康仕寿a, 代由勇a, 刘国磊a, 陈延学a, 梅良模a   

  1. a School of Physics, National Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;
    b Department of Applied Physics, School of Information Science and Engineering, Shandong Agricultural University, Taian 271018, China
  • 收稿日期:2012-11-18 修回日期:2013-01-06 出版日期:2013-04-01 发布日期:2013-04-01
  • 基金资助:
    Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11204164), the National Natural Science Foundation of China (Grant No. 11174184), the National Basic Research Program of China (Grants Nos. 2013CB922303 and 2009CB929202), and the National Funds for Distinguished Young Scholars of China (Grant No. 51125004).

Oscillation of coercivity between positive and negative in MnxGe1-x:H ferromagnetic semiconductor films

Qin Yu-Feng (秦羽丰)a b, Yan Shi-Shen (颜世申)a, Xiao Shu-Qin (萧淑琴)a, Li Qiang (李强)a, Dai Zheng-Kun (代正坤)a, Shen Ting-Ting (沈婷婷)a, Yang Ai-Chun (杨爱春)a, Pei Juan (裴娟)a, Kang Shi-Shou (康仕寿)a, Dai You-Yong (代由勇)a, Liu Guo-Lei (刘国磊)a, Chen Yan-Xue (陈延学)a, Mei Liang-Mo (梅良模)a   

  1. a School of Physics, National Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;
    b Department of Applied Physics, School of Information Science and Engineering, Shandong Agricultural University, Taian 271018, China
  • Received:2012-11-18 Revised:2013-01-06 Online:2013-04-01 Published:2013-04-01
  • Contact: Dai You-Yong E-mail:yydai@sdu.edu.cn
  • Supported by:
    Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11204164), the National Natural Science Foundation of China (Grant No. 11174184), the National Basic Research Program of China (Grants Nos. 2013CB922303 and 2009CB929202), and the National Funds for Distinguished Young Scholars of China (Grant No. 51125004).

摘要: Amorphous MnxGe1-x:H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron co-sputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x:H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6:H film, the inverted Hall loop is also observed at 30 K, which is in consistence with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.

关键词: magnetic semiconductor, hydrogenation, MnxGe1-x, antiferromagnetic coupling

Abstract: Amorphous MnxGe1-x:H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron co-sputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x:H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6:H film, the inverted Hall loop is also observed at 30 K, which is in consistence with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.

Key words: magnetic semiconductor, hydrogenation, MnxGe1-x, antiferromagnetic coupling

中图分类号:  (Magnetic semiconductors)

  • 75.50.Pp
75.70.Ak (Magnetic properties of monolayers and thin films) 75.50.Ee (Antiferromagnetics) 73.61.Jc (Amorphous semiconductors; glasses)