Exotic physical properties in metallic perovskite LaRuO3: Strong evidence for Hund metal

The Hund's coupling rule is of fundamental importance in atomic physics. It also plays a key role in the determination of physical properties in strongly correlated electron systems where the Fermi energy lies in multiple bands. Here we report a thorough investigation of a rarely studied 4d perovskite oxide LaRuO₃ by a suite of measurements including transport, magnetization, specific heat, thermoelectric power, thermal conductivity, and neutron and x-ray diffraction. Our results are consistent with theoretical predictions, which makes LaRuO₃ an exemplary Hund metal.