ELECTRONIC-STRUCTURE OF YTTRIUM-OXIDE

被引:104
作者
JOLLET, F [1 ]
NOGUERA, C [1 ]
THROMAT, N [1 ]
GAUTIER, M [1 ]
DURAUD, JP [1 ]
机构
[1] LAB PHYS SOLIDE,F-91405 ORSAY,FRANCE
来源
PHYSICAL REVIEW B | 1990年 / 42卷 / 12期
关键词
D O I
10.1103/PhysRevB.42.7587
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The electronic structure of stoichiometric Y2O3 is studied both theoretically and experimentally. X-ray absorption, performed through total-yield measurements at the K and LII edges of yttrium atoms and the K edge of oxygen atoms, through total-yield measurements has given access to empty states of various orbital characters in the conduction band. The shape of the valence band was obtained by means of photoemission spectroscopy. These results are compared with self-consistent, semiempirical tight-binding calculations applied to clusters of increasing sizes, which lead to local densities of states. We show that the quasi-octahedral local environment of the yttrium atoms is responsible for the splitting of their d levels. However, this ligand-field approach is not sufficient to account for the yttrium and oxygen K thresholds, nor for the shape of the valence band for which band effects are important. The two-peak structure of the oxygen K edge results from the hybridization of the O p orbitals with the eg and t1u states on the yttrium atoms. Three peaks are detected in the valence band: We show that they suggest the existence of direct-hopping terms between neighboring oxygen atoms. Finally, the various calculations have given an estimate of the degree of covalency of the Y-O bond. © 1990 The American Physical Society.
引用
收藏
页码:7587 / 7595
页数:9
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