Open AccessCorrelation of the local and the macroscopic properties of high‐temperature superconductors: EXAFS data analysis
Author(s) -
Menushenkov Alexey
Publication year - 2003
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/s0909049503007982
Subject(s) - extended x ray absorption fine structure , superconductivity , antibonding molecular orbital , antiferromagnetism , condensed matter physics , neutron scattering , spectral line , high temperature superconductivity , oxide , chemistry , materials science , physics , electron , absorption spectroscopy , scattering , atomic orbital , organic chemistry , astronomy , quantum mechanics , optics
Based on temperature‐dependent EXAFS studies of Ba 1− x K x BiO 3 superconducting oxide, a model of the relationship between the local crystal and the local electronic structures has been proposed. Oxygen ions were found to vibrate in a double‐well potential and their vibrations are correlated with the local electron pair transfer due to the dynamical exchange BiO 6 ↔ Bi 2 O 6 , where 2 denotes the hole pair in the antibonding Bi 6 s O2 p σ* orbital of the octahedral complex. The similarity of the EXAFS spectra features of Ba 1− x K x BiO 3 and La 2− x Sr x CuO 4 allowed us to propose a similar model for Cu‐based superconducting oxides. The model, in a common approach, explains the antiferromagnetic state, metal–insulator phase transition and the appearance of superconductivity at Sr 2+ doping of La 2 CuO 4 , and eliminates discrepancy between the neutron‐scattering and EXAFS data.