Open AccessTHE 2Δ0/(kBTc) AND THE PARAMETERS OF THE PHONON SPECTRUM FOR AMORPHOUS SUPERCONDUCTORS
Author(s) -
Xun Cao
Publication year - 1986
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.35.397
Subject(s) - superconductivity , condensed matter physics , physics , phonon , amorphous solid , coupling constant , coupling (piping) , spectrum (functional analysis) , bcs theory , quantum mechanics , materials science , pairing , chemistry , metallurgy , organic chemistry
In this paper, we propose a formula (2△0)/(kBTc)=4.95[1-T01/2/A(1/(λω0)+1/(20λ)+1/(20))], it can describe well the relations between 2△0/(kBTc) and the parameters of the phonon spectrum of disordered and amorphous superconductors for the non-transition metals and their alloys. Here T0 =0.66K, A =1/5K1/2, λ is electron-phonon coupling constant, is the average phonon frequency and ω0 the high frequency cutoff of the effective phonon spectrum a2F(ω). The values of 2△0/(kBTc) of disordered and amorphous superconductors which have the known parameters of the phonon spectrum have been calculated. Agreement with experiment is within a few percent. We show that the amorphous superconductor of non-transition metals and alloys is either a strong coupling superconductor which has a 2△0/(kBTc) valve much larger than the BCS theory value or a weak coupling superconductor which has a considerable smaller one than the BCS theory value.