Abstract
Ab initio pseudopotential calculations are performed for the electronic structure of the low- intermetallics C and the related nonsuperconducting compound LuNiBC. Electronic structures of the two compounds are compared in great detail, especially in terms of the Fermi surfaces and the symmetry-decomposed density of states (DOS) near the Fermi level. The estimated electron-phonon coupling constant λ (0.8–1.1) from the heat-capacity data as well as from the calculated DOS at indicates that of C is reasonably well explained by the conventional Bardeen-Cooper-Schrieffer mechanism with intermediate coupling strength. The relatively high arises from the large DOS at the Fermi level. Absence of superconductivity in LuNiBC may be understood to be due to the reduced DOS at . Unlike the high- cuprates, the low- C does not have the half-filled σ-antibonding bands and its electronic structure is almost three dimensional despite the layered atomic structure.
- Received 28 February 1995
DOI:https://doi.org/10.1103/PhysRevB.52.4592
©1995 American Physical Society