Superconducting Order Parameter and the Phonon Profile In the Bismuth Family of Compounds

NESTOR E. MASSA; JUAN CAMPA; ISIDORO RASINES; CARLOS FAINSTEIN; GLADYS NIEVES

Journal of the Argentine Chemical Society

ASOCIACIÓN QUÍMICA ARGENTINA

Lugar: Buenos Aires; Año: 1996 vol. 84 p. 7 - 12

0365-0375

We discuss far infrared measurements of superconducting compounds members of the Bismuth family. We find discrete changes in the areas of first and second order phonon band profiles near the superconductor critical temperature (Tc). These show a plateau at temperatures well above Tc. This behavior is coincident with the observation of the superconductor gap and polaron formation at temperatures well above Tc. We conclude that changes in the vibrational bands may be interpreted as consequence of polaron condensation and, thus, taken as evidence of strong electron-phonon interactions in high Tc superconductors.