摘要
本文测定了六个钛榴石样品(TiO_(2)含量9.70—15.34%)的穆斯堡尔谱。所测样品的穆谱均星复杂谱形。对拟谱方法作了改进。观察到一组新的组分谱。确定钛榴石穆谱由六套四极双峰组成。它们被分别指派给Fe^(2+)(X)、Fe^(2+)(Y)、Fe^(3+)(Y)、Fe^(3+)(Z)和两种电子离域Fe^(3+)(Z)⇋Fe^(2+)(X)、Fe^(3+)(Z)⇋Fe^(2+)(Y)。根据本样品的单晶结构数据对谱线指派和有关穆斯堡尔参数作了阐述。求出了各样品中阳离子的位置分布。阳离子在四面体(Z)位上的绝对量为Fe^(3+)>Al^(3+)、Ti^(4+)。Fe^(3+)比Ti^(4+)优先占据Z位。本样品中普遍存在三价钛。Ti^(3+)/∑Ti范围为3.83%至9.26%。Fe^(2+)/ΣFe比值范围为732%至10.01%。给出钛进入石榴石结构的五种替代方式。并对从这些实验结果可能获取的地质信息作了探讨。
Mössbauer Spectra of six schorlomite samples with the TiO_(2) contents varying from 9.70 to 15.34 weight percent have been measured.The measured Mossbaner spectra have complex shapes.Some improvement of fitting procedure has been made.One new doublet is observed,the spectra of these schorlomites consist of six doublets.These doublets have been assigned to Fe^(2+)(X)、Fe^(2+)(Y)、Fe^(3+)(Y)、Fe^(3+)(Z)and two electron delocalizations,Fe^(3+)(Z)⇋Fe^(2+)(X)、Fe^(3+)(Z)⇋Fe^(2+)(Y),respectively.The assignment of iron absorption doublets and the obtained Mssbauer parameters are discussed based on the single crystal structure data of the sample studied in this work.Cation distributions in the schorlomites have been given.The absolute amount of cations at tetrahadral(Z)site is Fe^(3+)>Al^(3+),Ti^(4+),and Fe^(3+) has the preference for Z site as compared with Ti^(4+).All the six samples contain Ti^(3+).Ti^(3+)/ΣTi ratios range from 3.83%to 9.26%.Fe^(2+)/ΣFe ratios vary from 7.32%to 10.01%.Five types of substitutions have presented for the Ti entering garnet structure.Finally a preliminarydiscussion on geological information which can be extracted from these experimental results has been given.
作者
牟保磊
吴功保
Mu Baolei;Wu Gongbao(Department of Geology,Peking University;Institute of Mineral Deposits, the Chinese Academy of Geological Sciences)
出处
《地质学报》
1985年第4期304-318,共15页
Acta Geologica Sinica
