Abstract
A local-density electronic-band-structure calculation was performed for a recently discovered non-copper-layered perovskite superconductor, . It was found that the electronic structure near the Fermi energy is essentially described by antibonding bands of the Ru dɛ and O pπ states. Although two holes in the bands are predominantly situated in a dɛ(xy)-pπ state in the ab plane, the hole occupations in the other dɛ-pπ states vertical to the plane are not negligibly small, possibly in conjunction with the smallness of tetragonal distortion of the octahedron. Associated with the antibonding dɛ-pπ bands, the density of states at the Fermi energy is relatively high (4.36 states/eVcell) but not enough to account for the observed specific-heat constant and temperature-independent magnetic susceptibility . We found a large Stoner factor, which may explain most of the mass enhancement involved in . Certain similarities and dissimilarities in the electronic properties to the cuprate superconductors are discussed.
- Received 8 November 1994
DOI:https://doi.org/10.1103/PhysRevB.51.1385
©1995 American Physical Society