磁记录用的BaFe_（12－2x）CoxTixO_（19）微粉的晶化特性研究

Study of the Crystallization Properties of BaFe_(12-2x)CoxTixO_(19) Powders for Magnetic Recording

采用玻璃晶化法制备适合磁记录用的Ｃｏ－Ｔｉ替代型钡铁氧体ＢａＦｅ_（１２－２ｘ）Ｃｏ_ｘＴｉ_ＸＯ_（１９）（ｘ＝０，０．５，０．６，０．７，０．８，０．８５，０．９）微粉。动态（变温）Ｘ射线衍射和ＤＴＡ曲线分析表明，在非晶薄片基体的晶化过程中，随热处理温度的升高，首先晶化出ＢａＢ_２Ｏ_４和Ｂａ_２Ｂ_２Ｏ_７相，随后出现钡铁氧体相；温度到达８５０℃后，非磁性相消失，仅剩有磁性的钡铁氧体相．晶化过程为先成核而后长大。有关晶化条件对钡铁氧体微粉粒子尺寸及分布的影响、对形貌的影响也作了详细的探讨。

Co and Ti substituted barium ferrite BaFe12-2x CoxTixO19 (x =0, 0. 5, 0. 6, 0. 7,0. 8, 0. 85, 0. 9) particles were prepared by glass-crystallization method with the glass BaCO3-B2O3-Fe2O3 system. The X ray diffraction of the glass heat-treated under various conditions, and of that at different temperatures indicated that the non-magnetic phase bariumborate (BaB2O4) was crystallized first, and then the magnetic phase barium ferrite appeared.It was found that after annealing at 850℃ there was only the crystalline magnetic phase. The nucleating and growing temperatures were obtained by comparing the X ray diffraction spectra and DTA curves. The effect of crystallization process of glass-flakes on particle size and its distribution and the morphology of barium ferrite powders have also been investigated.