Non-Phononic Mechanism of the Superconductivity in A15 Compounds
Abstract
A non-phononic mechanism based on Geilikman’s model is proposed for the superconductivity of the A15 compounds with high transition temperatures Tc. The band structure near the Fermi level \varepsilonF in these compounds is characterized by coexsistence of the very narrow \varGamma12-subbands called the ‘d-bands’ and other wide bands called the ‘s-bands’. The Coulomb interaction between the s- and d-electrons causes an indirect attractive interaction between the s-electrons via the particle-hole pair excitation in the d-electron system. The superconductivity in the s-electron system forces the d-electrons to form Cooper pairs. The structural phase transition redistributes the d-electrons to go away from \varepsilonF, being unfavourable in the superconducting phase. This model can explain successfully the interference of the superconductivity with the structural transition observed in V3Si and Nb3Sn.
- Publication:
-
Journal of the Physical Society of Japan
- Pub Date:
- January 1985
- DOI:
- 10.1143/JPSJ.54.29
- Bibcode:
- 1985JPSJ...54...29K
- Keywords:
-
- Band Structure Of Solids;
- Superconductivity;
- Transition Temperature;
- Coulomb Collisions;
- Electron Scattering;
- Niobium Stannides;
- Phase Transformations;
- Vanadium Compounds;
- Solid-State Physics