We have examined the effect of nonmagnetic impurity on the superconducting gap of La2-xSrx(Cu1-yZny)O4 and Y(Ni1-xPtx)2B2C from the mixed-state specific heat C(T,H). In La2-xSrxCuO4, impurity scattering leads to an appearance of a finite density of states (DOS) at the Fermi level, consistent with d-wave pairing state with nonmagnetic impurity scattering. In contrast, nonmagnetic impurity scattering in YNi2B2C leads to a smearing of the gap anisotropy and the opening of a gap in the DOS over the whole Fermi surface, though C(T, H) for pure compound suggests the presence of anisotropic gap. This indicates YNi2B2C is a highly anisotropic s-wave superconductor.
- Specific heat
- Superconducting gap
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering