Carrier doping to the Mott insulator is essential to produce highly correlated metals with emergent properties. The pyrochlore ruthenates Pr2Ru2O7 (Ru 4d electron number n=4) and Ca2Ru2O7 (n=3) are a Mott insulator and a magnetic bad metal, respectively, due to the strong electron correlation. We investigate magnetotransport properties of (Pr1-xCax)2Ru2O7 in a whole band-filling range, 0≤x≤1. With increasing hole doping x, the system undergoes an insulator-metal transition. When Ca2Ru2O7 is doped with electrons (0.5<x<0.9), the enhanced coupling among Ru 4d spins produces a ferromagnetic-metal phase with a large anomalous-Hall angle up to 2%. We discuss the electronic phase transitions in (Pr1-xCax)2Ru2O7 in view of Hund's metal.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics