ISSN:
1090-6487
Keywords:
74.72.Yg
;
78.70..Dm
;
61.66.Fn
;
63.20.Ry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The temperature dependence of the x-ray absorption spectra above the L 3 absorption edge of bismuth in the superconducting oxide Ba0.6K0.4BiO3 are investigated. It is found that the local structure is different from the simple cubic structure indicated by x-ray and neutron-diffraction data. It is shown that the oxygen atoms move in an anharmonic double-well potential arising as a result of the existence of two nonequivalent types of octahedral environments of bismuth. Vibrations in such potential modulate the Bi-O bond lengths at the low frequency of the rotational (“tilting” type) mode of the oxygen octahedra and thus give rise to a strong electron-phonon interaction, which explains the quite high superconducting transition temperatures T c ∼30 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1134/1.567788
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