SHS法制备NiZnFe_2O_4预烧料的工艺研究

Research on Technics in SHS Prepared NiZnFe_2O_4 Pre-sintered Powders

利用自蔓延高温合成的方法制备出纯度较高的NiZnFe2O4预烧料,并且利用XRD图谱,通过外推法及Vegard定律等分析了SHS法中保温时间及压坯相对密度对产物结构的影响.结果表明:NiZnFe2O4的标准图谱中应当去掉原有的第三条特征峰,同时添加(622)晶面上的一条特征峰;SHS合成的NiZnFe2O4预烧料中还有少量残余的Fe2O3,其在产物中的质量分数不超过4%,且随着保温时间的延长而减少;随着粉料压坯相对密度(ρr)的提高,预烧料的主相,即固溶体NiZnFe2O4中所固溶的ZnFe2O4的含量增多,且在相对密度为57%～63%时,其摩尔分数接近配方比例.

Prepared were NiZnFe2O4 pre-sintered powders by SHS method. By means of XRD patterns analysed were the influence of soak time and relative density of powers on the structure of product in SHS method. The results show that the standard atlas of NiZnFe2O4 should delete the third character peak and add the peak of (622); little remains of Fe2O3 are found in NiZnFe2O4 pre-sintered powders produced by SHS ,whose wt% is not more than 4%. And the remains amounts will decrease with increase of soak time in calcination. The content of ZnFe2O4 in NiZnFe2O4 will increase with the increase of the relative density of powders.