新疆铬铁矿的穆斯堡尔谱研究

新疆铬铁矿的穆斯堡尔谱研究 MOSSBAUER EFFECT STUDY OF A NATURAL CHROMITE FROM XIN JIANG DEPOSIT 陈义龙 Chen Yilong Xu Binfu Cheng Jigao 1 2 3 first-author 徐斌富 1 2 3 程寄皋 1 2 3 武汉大学物理系 武汉大学物理系 Department of Physics,Wuhan Univeasity Department of Physics,Wuhan Univeasity 武汉钢铁学院 武汉钢铁学院 武汉大学物理系武汉钢铁学院 武汉大学物理系武汉钢铁学院 在20～70K 的温度范围内对新疆铬铁矿进行了穆斯堡尔谱研究。根据低温谱形,将全谱分解成三套双峰,其中第Ⅰ、Ⅱ套是四面体中的 Fe 2+ 产生的。第Ⅲ套是八面体中的Fe 3+ 产生的,这几套谱的同贡异能移及其与温度的关系证实了这种分解的正确性,从电四极分裂与温度的关系确定四面体中 Fe 2+ 离子能级因 Jahn-Teller 效应而分裂的宽度相应为212和179cm -1 。对于此种铬铁矿三价铁与二价铁的含量比为 Fe 3+ /Fe 2+ =0.35±0.03。本工作有力地支持了 Fe 2+ 处于四面体和 Fe 3+ 处八面体的有序分布模型。 Mossbaner spectra of a natural chromite fron Xin Jiang deposit has been reorded at a wide temperature range between 20K and 750K.Based on the low temperature mossbauer patterns,all the spectra are fitted by three doublets: the two are attributed to the tetredral（A）site Fe 2+ ,the third to the oc- tahedral（B）site Fe 3+ .Such assignment was confirmed by detailed analysis of the temperature dependent center shifts and other parameters.The Mossbauer ratio Fe 2+ /Fe 3+ was determineted to be 0.35+0.03.T dependent quadrupole splittings of two doublets are interpreted in terms of John-Teller distortion which lifts the degeneracy of the Eg level by 212 and I79 cm -1 respectively. Thus our results strong support the ordered distribution with Fe 2+ in A site and Fe 3+ in B site. 穆斯堡尔效应 铬铁矿 次近邻效应 1991-04-01 2021-04-01 4