单轴M型SrFe12-xCrxO19超细粒子结构与磁性研究

采用溶胶-凝胶法制备了单轴M型锶铁氧体SrFe12-x_12-xCrx_xO 19₁₉(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_s在x≤04范围内增大，在x=02附近达到极大值.矫顽力Hc_c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-Fe2₂O3< 关键词： 锶铁氧体 3+')" href="#">Cr3+³⁺ 结构 磁性

Studies on structure and magnetic properties of uniaxial M-type SrFe12-x 12-xCrxxO1919 hexaferrite nano-crystalline

SrFe12-x_12-xCrx_xO19₁₉ (x=0—10) hexaferri te nanoparticles have been fabricated using a sol-gel technique for perpendicular magnetic recording. Experimental results have shown that the values of specific saturation mag netization, σs_s, increase for x≤04 as the Cr doping content incre ases, and reach maximum at x=02, while the coercivity, Hc_c, decreas es for x＜05 This feature is favorable to magnetic recording. It is also fou nd that the α-Fe2₂O3₃ non-magnetic phase appears after x=06 and remai ns to be a hexagonal magnetoplumbite phase for x=0—04 Magnetic measurem ents have revealed that Cr substitution can decrease the magnetization and incre ase the peak-widening for Hopkinson peak when doped with Cr3+³⁺.