Correlated metallic phase in a doped band insulator Sr1-xRh2O4

Transport and thermal properties were examined for the layered rhodium oxide beta-Sr1-xRh2O4. The parent compound SrRh2O4 is a band insulator. The introduction of Sr deficiencies results in an insulator-metal transition around x similar or equal to 0.2. The metallic phase for x > 0.2 is a strongly correlated Fermi liquid with an enhanced quasiparticle mass. The enhanced thermoelectric power of S similar to 150 mu V/K at 1000 K in this metallic phase suggests a potential of Sr1-xRh2O4 as a thermoelectric material.