Abstract
Photoemission and inverse photoemission studies of films show insulating character for x<3±0.3 as states derived primarily from the LUMO orbitals of are occupied. Metallic character is observed at higher Ca content as a second band of states is partially occupied. This band has mixed character since it is derived from the LUMO+1 orbitals of and the Ca s states. These states are responsible for superconductivity in .
- Received 30 June 1992
DOI:https://doi.org/10.1103/PhysRevB.46.7961
©1992 American Physical Society