中国物理B ›› 2016, Vol. 25 ›› Issue (12): 126102-126102.doi: 10.1088/1674-1056/25/12/126102

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Tuning of magnetic properties of aluminium-doped strontium hexaferrite powders

Xiao-Mei Ma(马小梅), Jie Liu(刘杰), Sheng-Zhi Zhu(朱生志), Hui-Gang Shi(史慧刚)   

  1. Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • 收稿日期:2016-06-22 修回日期:2016-08-18 出版日期:2016-12-05 发布日期:2016-12-05
  • 通讯作者: Hui-Gang Shi E-mail:shihuig@lzu.edu.cn

Tuning of magnetic properties of aluminium-doped strontium hexaferrite powders

Xiao-Mei Ma(马小梅), Jie Liu(刘杰), Sheng-Zhi Zhu(朱生志), Hui-Gang Shi(史慧刚)   

  1. Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • Received:2016-06-22 Revised:2016-08-18 Online:2016-12-05 Published:2016-12-05
  • Contact: Hui-Gang Shi E-mail:shihuig@lzu.edu.cn

摘要:

M-type Al-doped strontium ferrite powders (SrAlxFe2n-xO19, n=5.9) with nominal Al content of x=0-2.0 are prepared by traditional ceramic technology. The phase identification of the powders, performed using x-ray diffraction, shows the presence of purity hexaferrite structure and absence of any secondary phase. The lattice parameters decrease with increasing x. The average grain size of the powders is about 300 nm-400 nm at Al3+ ion content x=0-2.0. The room-temperature hysteresis loops of the powders, measured by using vibrating sample magnetometer, show that the specific saturation magnetization (σs) value continuously decreases while the coercivity (Hc) value increases with increasing x, and Hc reaches to 9759 Oe (1 Oe=79.5775 A/m) at x=2.0. According to the law of approach saturation, Hc value increases with increasing Al3+ ion content, which is attributed to the saturation magnetization (Ms) decreasing more rapidly than the magnetic anisotropy constant (K1) obtained by numerical fitting of the hysteresis loops. The distribution of Al3+ ions in the hexaferrite structure of SrAlxFe2n-xO19 is investigated by using 57Co Mössbauer spectroscopy. The effect of Al3+ doping on static magnetic properties contributes to the improvement of magnetic anisotropy field.

关键词: Al-doped, strontium ferrite powders, high coercivity

Abstract:

M-type Al-doped strontium ferrite powders (SrAlxFe2n-xO19, n=5.9) with nominal Al content of x=0-2.0 are prepared by traditional ceramic technology. The phase identification of the powders, performed using x-ray diffraction, shows the presence of purity hexaferrite structure and absence of any secondary phase. The lattice parameters decrease with increasing x. The average grain size of the powders is about 300 nm-400 nm at Al3+ ion content x=0-2.0. The room-temperature hysteresis loops of the powders, measured by using vibrating sample magnetometer, show that the specific saturation magnetization (σs) value continuously decreases while the coercivity (Hc) value increases with increasing x, and Hc reaches to 9759 Oe (1 Oe=79.5775 A/m) at x=2.0. According to the law of approach saturation, Hc value increases with increasing Al3+ ion content, which is attributed to the saturation magnetization (Ms) decreasing more rapidly than the magnetic anisotropy constant (K1) obtained by numerical fitting of the hysteresis loops. The distribution of Al3+ ions in the hexaferrite structure of SrAlxFe2n-xO19 is investigated by using 57Co Mössbauer spectroscopy. The effect of Al3+ doping on static magnetic properties contributes to the improvement of magnetic anisotropy field.

Key words: Al-doped, strontium ferrite powders, high coercivity

中图分类号:  (Structure of nanoscale materials)

  • 61.46.-w
75.75.-c (Magnetic properties of nanostructures)