中国物理B ›› 2004, Vol. 13 ›› Issue (11): 1969-1974.doi: 10.1088/1009-1963/13/11/038

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Effects of underlayer materials and substrate temperatures on the structural and magnetic properties of Nd2Fe14B films

M. Matsumoto1, A. Morisako1, S. Takei1, 马云贵2, 杨正2   

  1. (1)Department of Information Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan; (2)Research Institute of Magnetic Materials, Lanzhou University, Lanzhou 730000, China
  • 收稿日期:2003-12-18 修回日期:2004-06-21 出版日期:2004-11-20 发布日期:2005-06-20

Effects of underlayer materials and substrate temperatures on the structural and magnetic properties of Nd2Fe14B films

Ma Yun-Gui (马云贵)a, Yang Zheng (杨正)a, M. Matsumotob, A. Morisakob, S. Takeib    

  1. a Research Institute of Magnetic Materials, Lanzhou University, Lanzhou 730000, China; b Department of Information Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
  • Received:2003-12-18 Revised:2004-06-21 Online:2004-11-20 Published:2005-06-20

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摘要： Thin films of Nd_2Fe_{14}B were fabricated on heated glass substrates by dc magnetron sputtering. Different material underlayers (Ta, Mo, or W) were used to examine the underlayer influence on the structural and magnetic properties of the NdFeB films. Deposited on a Ta buffer layer at 420℃, the 300 nm thick NdFeB films were shown to be isotropic. But when the substrate temperature T_s was elevated to 520℃, the Nd_2Fe_{14}B crystallites of (00l) plane were epitaxially grown on Ta (110) underlayer. In contrast, Mo (110) buffer layer could not induce any preferential orientation in NdFeB film irrespective of the substrate temperature or film thickness. The W buffer layer was found to be most effective for the nucleation of Nd_2Fe_{14}B crystallites with c-axis alignment perpendicular to the film plane when T_s<490℃. But at T_s=490℃ the magnetic layer became isotropic. The maximum coercivity obtained was about 995 kA/m for the 100nm film deposited on W underlayer at 490℃. These variations were tentatively explained in terms of the lattice misfit between the underlayer and the magnetic layer, combined with the considerations of underlayer morphologies.

关键词: Nd2Fe14B film, underlayer, substrate temperature, texture

Abstract: Thin films of Nd$_2$Fe$_{14}$B were fabricated on heated glass substrates by dc magnetron sputtering. Different material underlayers (Ta, Mo, or W) were used to examine the underlayer influence on the structural and magnetic properties of the NdFeB films. Deposited on a Ta buffer layer at 420℃, the 300 nm thick NdFeB films were shown to be isotropic. But when the substrate temperature $T_{\rm s}$ was elevated to 520℃, the Nd$_2$Fe$_{14}$B crystallites of (00l) plane were epitaxially grown on Ta (110) underlayer. In contrast, Mo (110) buffer layer could not induce any preferential orientation in NdFeB film irrespective of the substrate temperature or film thickness. The W buffer layer was found to be most effective for the nucleation of Nd$_2$Fe$_{14}$B crystallites with c-axis alignment perpendicular to the film plane when $T_{\rm s}$ <490℃. But at $T_{\rm s}$ =490℃ the magnetic layer became isotropic. The maximum coercivity obtained was about 995 kA/m for the 100nm film deposited on W underlayer at 490℃. These variations were tentatively explained in terms of the lattice misfit between the underlayer and the magnetic layer, combined with the considerations of underlayer morphologies.

Key words: Nd2Fe14B film, underlayer, substrate temperature, texture

中图分类号:  (Nucleation and growth)

  • 68.55.A-
75.70.Ak (Magnetic properties of monolayers and thin films) 61.66.Fn (Inorganic compounds) 75.50.Vv (High coercivity materials)