The ${\mathrm{BaSn}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Sb}}_{\mathit{x}}$${\mathrm{O}}_3$ perovskite solid solution exists for 0.0 ≤x≤0.2. The best electrical conductivity occurs for x near 0.15, and is essentially temperature independent from 300 to 5 K. The materials, although conductive, do not become superconducting to temperatures as low as 0.05 K. We propose that the difference between metal 5s–oxygen 2p and metal 6s–oxygen 2p bonding in solids accounts for this behavior.

• Received 7 May 1990

DOI:https://doi.org/10.1103/PhysRevB.42.4815