LaMAl11O19(M＝Mg,Fe)的化学键性质和穆斯堡尔谱研究

人工晶体学报 ›› 2001, Vol. 30 ›› Issue (2): 198-202.

LaMAl11O19(M＝Mg,Fe)的化学键性质和穆斯堡尔谱研究

高发明;李东春;张思远

.燕山大学材料化工学院,;中国科学院长春应用化学研究所,

出版日期:2001-02-15 发布日期:2021-01-20
基金资助:
国家自然科学基金(29871029)

Investigation of Chemical Bond Properties and MossbauerIsomerShifts in Magnetoplumbite Type Compound LaMAl11O19(M＝Mg,Fe)

GAO Fa-Ming;LI Dong-Chun;ZHANG Si-Yuan

Online:2001-02-15 Published:2021-01-20

摘要/Abstract

摘要： 利用复杂晶体化学键的平均能带模型研究了LaMAl11O19(M＝Mg,Fe)晶体的化学键性质。结果表明，La-O键只有3;的共价性，4f1格位却具有很强的共价特征。晶体中各格位共价次序为：La-O＜Al(5)-O＜Al(1)-O＜Al(4)-O＜Al(2)-O＜Al(3)-O＜M-O。其中2d格位和4e格位具有强的各向异性特征。利用由共价性和极化率定义的化学环境因子h计算了LaFeAl11O19中57Fe的穆斯堡尔同质异能位移和LaMgAl11O19∶Eu中151Eu的同质异能位移，所得结果与实验值一致。

关键词: LaMAl11O19;化学键;穆斯堡尔效应

Abstract: The chemical bond properties of the magnetoplumbite type compound LaMAl11O19(M＝Mg,Fe) have been studied by using the average band-gap model of the complex crystal chemical bond.The results show that covalency of La-O bond is only 3;,but 4f1 site has very high covalent character in each bond.The covalency for each bond obeys the following order:La-O＜Al(5)-O＜Al(1)-O＜Al(4)-O＜Al(2)-O＜Al(3)-O＜M-O.The anisotropy character in 2d site and 4e site of the crystals is revealed by calculating the chemical bond parameters.Mossbauer isomer shifts of Fe2+ ion in LaFeAl11O19 and Eu3+ ion in LaMgAl11O19 are calculated by using the chemical surrounding facter,h,definited by covalency and electronic polarizability,and the results are in agreement with the experimental values.

Key words: The chemical bond properties of the magnetoplumbite type compound LaMAl11O19(M＝Mg,Fe) have been studied by using the average band-gap model of the complex crystal chemical bond.The results show that covalency of La-O bond is only 3;,but 4f1 site has very high covalent character in each bond.The covalency for each bond obeys the following order:La-O＜Al(5)-O＜Al(1)-O＜Al(4)-O＜Al(2)-O＜Al(3)-O＜M-O.The anisotropy character in 2d site and 4e site of the crystals is revealed by calculating the chemical bond parameters.Mossbauer isomer shifts of Fe2+ ion in LaFeAl11O19 and Eu3+ ion in LaMgAl11O19 are calculated by using the chemical surrounding facter,h,definited by covalency and electronic polarizability,and the results are in agreement with the experimental values.

中图分类号:

高发明;李东春;张思远. LaMAl11O19(M＝Mg,Fe)的化学键性质和穆斯堡尔谱研究[J]. 人工晶体学报, 2001, 30(2): 198-202.

GAO Fa-Ming;LI Dong-Chun;ZHANG Si-Yuan. Investigation of Chemical Bond Properties and MossbauerIsomerShifts in Magnetoplumbite Type Compound LaMAl11O19(M＝Mg,Fe)[J]. Journal of Synthetic Crystals, 2001, 30(2): 198-202.