Abstract
We have measured the Raman spectra of polycrystalline from 25 to . A superconductivity-induced redistribution in the electronic Raman continuum was observed. Two pair-breaking peaks appear in the spectra, suggesting the presence of two superconducting gaps. The measured spectra were analyzed using a quasi-two-dimensional model in which two -wave superconducting gaps open on two sheets of Fermi surface. For the gap values we have obtained ( ) and ( ). Our results suggest that a conventional phonon-mediated pairing mechanism occurs in the planar boron bands and is responsible for the superconductivity of .
- Received 30 March 2001
DOI:https://doi.org/10.1103/PhysRevLett.87.157002
©2001 American Physical Society