【摘要】 采用燃烧合成法制备了ZnFe₂O₄。Ni-ZnFe₂O₄和MnFe₂O₄尖晶石型软磁铁氧体粉体。通过Mssbauer谱对燃烧合成产物及其热处理后的物相组成进行分析。研究结果表明,燃烧合成MFe₂O₄(Mo为Mg²⁺,Mn²⁺,Ni²⁺,Zn²⁺等)是在非平衡状态下进行的,其特点是燃烧温度高,降温速率快,因而使产物中存在部分亚稳相和中间相。燃烧合成的MnFe₂O₄在1100℃热处理2 h后,产物中的Fe₂O₃与Mn的氧化物几乎未发生反应生成尖晶石相;1200℃热处理2 h的产物经空气和水中淬火后,均可得到结构较为完整的单相MnFe₂O₄铁氧体,但与传统固相反应法的本质区别是阳离子趋向反型分布,说明MnFe₂O₄的形成与周围气氛及温度有着十分重要的关系。更多还原

【Abstract】 Spinel ZnFe2O4 , Ni-ZnFe2O4 and MnFe2O4 powders were prepared by the combustion synthesis method. The phase composition of the combustion products and with their subsequent heat-treatment were studied by Mossbauer spectroscopy. The results show that combustion synthesis is carried on at a non-equilibrium condition, that lets to the formation of metastable and intermediate phases due to the high combustion temperature and high cooling rate. After heat-treatment of 1100℃ for 2 h, almost no spinel ferrite was formed by reaction of Fe2O3 with manganese oxide. While after heat-treated at 1200℃ and quenched in the air or in the water, single spinel-phase MnFe2O4 ferrite with nearly perfect form were obtained, Difference with those prepared by conventional solid state method, the inverse cations distribution is obtained. It indicates that the formation of MnFe2O4 depends on the atmosphere and temperature.更多还原