Open AccessTowards a limited XANES refinement in strongly correlated systems
Author(s) -
Ignatov Alexander
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049501000231
Subject(s) - xanes , antiferromagnetism , superconductivity , atom (system on chip) , electronic structure , electron , condensed matter physics , atomic physics , range (aeronautics) , physics , materials science , molecular physics , spectroscopy , nuclear physics , quantum mechanics , computer science , composite material , embedded system
Three components of O1 atom displacements have been derived from the direct fit of the polarized E || ab Cu K ‐edge XANES spectrum of Nd 1.85 Ce 0.15 CuO 4‐δ superconductor. The best fit is achieved for a 60 to 40% mixture of 2x2 undistorted antiferromagnetic and modified charge density wave (MCDW) domains. The local structure of the MSDW is characterized by correlated displacements of ΔO1 || =0.12±0.04, ΔO1 ⊥ =0.25±0.08, and ΔO1 z =0.12±0.1 Å. An agreement factor over the range of 8980‐9040 eV is 2‐3 times smaller than it may be obtained from single‐electron MS calculations. This improvement comes from accounting for many‐body excitations and the relationship between electronic and local structure in the CuO 2 planes.