中文摘要：

尖晶石型矿物因其阳离子在氧四面体和氧八面体中所占比例的不同而分为正尖晶石、反尖晶石和过渡的无序结构尖晶石。本文以微米级锌铁正尖晶石（Zn Fe2O4）为初始研究对象,通过扫描电子显微镜（SEM）、X射线衍射（XRD）、X射线吸收精细结构谱（XAFS）、差热-热重分析（DTA-TGA）、磁性测试（M-H、ZFC-FC）等矿物学、热学和磁学测试手段综合分析了温度对其阳离子配位的影响。结果显示,随着温度的升高,原正尖晶石结构中四面体的ZnⅡ会逐渐与八面体中的FeⅢ发生交换,910℃左右时阳离子的交换速率出现最大值,并在1 200℃加热24 h后达到热动力学平衡,此时晶胞参数a从8.440 7减小到了8.437 2;同时尼尔温度（TN）由13 K升到了27 K,反映了由反铁磁性向亚铁磁性过渡的磁结构变化。本文研究认为,由粒径不同带来的体系能量的差异是造成微米级Zn Fe2O4在高温下阳离子交换行为与纳米级颗粒截然相反的根本原因。

英文摘要：

Spinel-type minerals can be classified into normal, inverse and disordered structure according to the different proportions of cation site occupancy at metal-oxygen tetrahedron and octahedron. In this paper, the authors chose micron-scale franklinite（ Zn Fe_2O_4） as the original research object. Mineralogical, thermal and magnetic measurements, such as SEM, XRD, XAFS, DTA-TGA, M-H, ZFC-FC, were employed to investigate the influence and mechanism of high temperature on the cation site occupancy. The results show that the cationic exchange occurs between ZnⅡ and FeⅢ in tetrahedral and octahedral sites, respectively, along with the increasing temperature. The maximum exchange rate appears at around 910°C. Thermodynamic and kinetic equilibrium is realized after the sample is heated at 1 200℃ for 24 hours. The cell parameter（ a） decreases from 8. 440 7 A to8 437 2 A, and the Neel temperature（ TN） increases from 13 K to 27 K, changing antiferromagnetic order into the ferrimagnetic one. The particle size influences the energy of system, causing the completely opposite performance of cationic exchange for micro-Zn Fe_2O_4 and nano-Zn Fe_2O_4 at high temperature.