Open AccessTHE ELECTRONIC STRUCTURE AND SUPERCONDUCTIVITY FOR （Ｂａ1-xＫx）ＢｉＯ３
Author(s) -
Yuemao Shen,
Zhipeng Zhang,
Chen Long-Hai,
Huang Mei-Chun
Publication year - 1996
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.45.1737
Subject(s) - superconductivity , x ray absorption fine structure , electronic structure , condensed matter physics , materials science , percolation theory , valence (chemistry) , supercell , penetration depth , spectroscopy , physics , quantum mechanics , thunderstorm , meteorology , conductivity
Electronic structure for BKB has been calculated by using LMTO-ASA-Supercell method based on the X-ray absorption fine structure (XAFS) spectroscopy measurements. Measurements show that Bi posseses two valence states and 5 and their Bi— bond lengths are diffferent, the difference decreases with the increase of K concentration. Calculations are performed on five samples namely 441241226412226.Results from the calculations show that 404and (314)are semiconductors with gaps of 1.6eV and 1.5eV, respectively. Other samples are metals. Total energy analysis shows that (314) is not stable, so that the extreme value of x is 0.5. The BKB electronic structures at x=0.1 to 0.5 are calculated by combining the probability with sample's Bernoull's distribution. Superconducting transition temperature Tc of BKB is suddenly changed when x approximates to 0.25. The experimental data are close to the prediction values of percolation theory.