单轴M型SrFe_(12-x)Cr_xO_(19)超细粒子结构与磁性研究  

Studies on structure and magnetic properties of uniaxial M-type SrFe_(12-x)Cr_xO_(19) hexaferrite nano-crystalline

作　　者：方庆清[1] 焦永芳[1] 李锐[1] 汪金芝[1] 陈辉[1] 

机构地区：[1]安徽大学磁性材料研究中心,物理与材料科学学院,合肥230039

出　　处：《物理学报》2005年第4期1826-1830,共5页Acta Physica Sinica

基　　金：安微省学术和技术带头人基金 (批准号 :0 10 80 2 10 )资助的课题~~

摘　　要：采用溶胶 凝胶法制备了单轴M型锶铁氧体SrFe1 2 -xCrxO1 9(x =0— 1)超细晶粒 .实验结果表明 ,随掺杂量x的增大 ,质量饱和磁化强度σs 在x≤ 0 4范围内增大 ,在x =0 2附近达到极大值 .矫顽力Hc 在x <0 5的范围内单调降低 ,这对于用作高密度磁记录材料非常有利 .当x≤ 0 4时 ,样品是单相结构 ,在x =0 6以后出现非磁性相α Fe2 O3和其他杂相 .实验还发现 ,Hopkinson效应除了与晶体结构和外加磁场强度有关外 ,掺杂含量x也将影响Hopkinson效应 ,随着x的增加 ,Hopkinson峰值降低 ,峰宽展宽 .SrFe12-xCrxO19 (x = 0-1.0) hexaferrite nanoparticles have been fabricated using a sol-gel technique for perpendicular magnetic recording. Experimental results have shown that the values of specific saturation magnetization, a., increase for x <= 0.4 as the Cr doping content increases, and reach maximum at x = 0. 2, while the coercivity, H-c, decreases for x < 0. 5. This feature is favorable to magnetic recording. It is also found that the alpha-Fe2O3 non-magnetic phase appears after x = 0.6 and remains to be a hexagonal magnetoplumbite phase for x = 0-0.4. Magnetic measurements have revealed that Cr substitution can decrease the magnetization and increase the peak-widening for Hopkinson peak when doped with Cr3+.

关 键 词：锶铁氧体 磁性 溶胶-凝胶法 晶体单相结构 

分 类 号：TM271[一般工业技术—材料科学与工程]