Tuning of magnetic properties of aluminium-doped strontium hexaferrite powders  

作　　者：马小梅 刘杰 朱生志 史慧刚 

机构地区：[1]Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China

出　　处：《Chinese Physics B》2016年第12期344-349,共6页中国物理B（英文版）

摘　　要：M-type Al-doped strontium ferrite powders （SrA1xFe2n-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 He 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 （Kl） 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 Mtssbauer spectroscopy. The effect of Al3＋ doping on static magnetic properties contributes to the improvement of magnetic anisotropy field.M-type Al-doped strontium ferrite powders （SrA1xFe2n-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 He 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 （Kl） 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 Mtssbauer 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 

分 类 号：TM27[一般工业技术—材料科学与工程]