Numéro
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
Page(s) C2-481 - C2-483
DOI https://doi.org/10.1051/jp4/1997060
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure

J. Phys. IV France 7 (1997) C2-481-C2-483

DOI: 10.1051/jp4/1997060

Angular-Dependence in the K Pre-Edge XANES of Cubic Crystals : The Separation of the Empty Metal eg and t2g States of NiO and FeO

D. Heumann, G. Dräger and S. Bocharov

Fachbereich Physik der Martin-Luther-Universität, 06108 Halle, Germany


Abstract
It is well known that by applying the angular dependence of the dipole transition matrix elements on the K XANES of single-crystal samples, the different pm-like DOS components (m = x,y,z) of the empty states can be well resolved. Analyzing quadrupole transitions in the pre-edge absorption region allows to fulfill a symmetry resolution of the different dm-states (m = xy ,xz, yz,x2-y2,z2). This has been done for the first time at the cubic single-crystals NiO and FeO, where we could differentiate between eg and t2g components of the empty states using the orientation dependence of the absorption spectra. The Cu K XANES of tetragonal Bi2Sr2CaCU2O8 could be also resolved into the nondegenerated pm- and dm-like components. The method will be demonstrated and results for NiO, FeO and Bi2Sr2CaCU2O8 are presented and discussed.



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