中国物理B ›› 2009, Vol. 18 ›› Issue (4): 1647-1652.doi: 10.1088/1674-1056/18/4/061

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

First principles study on the magnetocrystalline anisotropy of Fe--Ga magnetostrictive alloys

郑蕾, 蒋成保, 尚家香, 徐惠彬   

  1. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
  • 收稿日期:2008-02-26 修回日期:2008-10-22 出版日期:2009-04-20 发布日期:2009-04-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 50471003 and No.50531010) and the New Century Program for Excellent Talents of Ministry of Education of China (Grant No NCET-04-0165).

First principles study on the magnetocrystalline anisotropy of Fe--Ga magnetostrictive alloys

Zheng Lei(郑蕾), Jiang Cheng-Bao(蒋成保), Shang Jia-Xiang(尚家香), and Xu Hui-Bin(徐惠彬)   

  1. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
  • Received:2008-02-26 Revised:2008-10-22 Online:2009-04-20 Published:2009-04-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 50471003 and No.50531010) and the New Century Program for Excellent Talents of Ministry of Education of China (Grant No NCET-04-0165).

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摘要： This paper investigates the electronic structure and magnetocrystalline anisotropy of Fe--Ga magnetostrictive material by means of the full potential-linearized augmented plane-wave method within the generalized gradient approximation. The 3d-orbit splitting of Fe atoms in D03, B2-like and L12 crystalline structures of Fe--Ga is calculated with consideration of the crystal field as well as the spin--orbit coupling effect. Because of the frozen orbital angular momenta of the 3d-orbit for Fe atoms in Fe--Ga magnetostrictive alloys and the spin--orbit coupling, the distribution of the electron cloud is not isotropic, which leads to the anisotropy of exchange interaction between the different atoms. A method on estimating the magnetocrystalline anisotropy of Fe--Ga alloys by means of calculating orbit-projected density of states for Fe atoms is performed. The anisotropic distribution of the electron cloud of Fe atoms in these three crystalline structures of Fe--Ga is studied based on the above method showing the highest magnetic anisotropy for B2-like structure. This qualitative method comes closer to physical reality with a vivid physical view, which can evaluate the anisotropy of electron cloud for 3d transition atoms directly. The calculated results are in good agreement with both the previous theoretical computation and the tested value on the magnetic anisotropy constant, which confirms that the electron cloud anisotropy of Fe atoms could well characterize the magnetocrystalline anisotropy of Fe--Ga magnetostrictive material.

Abstract: This paper investigates the electronic structure and magnetocrystalline anisotropy of Fe--Ga magnetostrictive material by means of the full potential-linearized augmented plane-wave method within the generalized gradient approximation. The 3d-orbit splitting of Fe atoms in D03, B2-like and L12 crystalline structures of Fe--Ga is calculated with consideration of the crystal field as well as the spin--orbit coupling effect. Because of the frozen orbital angular momenta of the 3d-orbit for Fe atoms in Fe--Ga magnetostrictive alloys and the spin--orbit coupling, the distribution of the electron cloud is not isotropic, which leads to the anisotropy of exchange interaction between the different atoms. A method on estimating the magnetocrystalline anisotropy of Fe--Ga alloys by means of calculating orbit-projected density of states for Fe atoms is performed. The anisotropic distribution of the electron cloud of Fe atoms in these three crystalline structures of Fe--Ga is studied based on the above method showing the highest magnetic anisotropy for B2-like structure. This qualitative method comes closer to physical reality with a vivid physical view, which can evaluate the anisotropy of electron cloud for 3d transition atoms directly. The calculated results are in good agreement with both the previous theoretical computation and the tested value on the magnetic anisotropy constant, which confirms that the electron cloud anisotropy of Fe atoms could well characterize the magnetocrystalline anisotropy of Fe--Ga magnetostrictive material.

Key words: Fe--Ga magnetostrictive alloy, magnetocrystalline anisotropy

中图分类号:  (Magnetic anisotropy)

  • 75.30.Gw
75.50.Bb (Fe and its alloys) 75.80.+q (Magnetomechanical effects, magnetostriction) 71.20.Be (Transition metals and alloys) 71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)) 61.66.Dk (Alloys )