Fully filling-controlled pyrochlore ruthenates: emergent ferromagnetic-metal state and geometrical Hall effect

Abstract

Carrier doping to the Mott insulator is essential to produce highly correlated metals with emergent properties. Pyrochlore ruthenates, Pr${}_2$Ru${}_2$O${}_7$ (Ru-$4d$ electron number, $n=4$) and Ca${}_2$Ru${}_2$O${}_7$ ($n=3$), are a Mott insulator and a magnetic bad metal, respectively, due to the strong electron correlation. We investigate magneto-transport properties of (Pr${}_{1-x}$Ca${}_x$)${}_2$Ru${}_2$O${}_7$ in a whole band-filling range, $0<x<1$. With increasing hole-doping $x$, the system undergoes an insulator-metal transition. When Ca${}_2$Ru${}_2$O${}_7$ 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 (Pr${}_{1-x}$Ca${}_x$)${}_2$Ru${}_2$O${}_7$ in view of Hund's metal.

6 pages, 4 figures

References in corpus (8)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Strong electronic correlations from Hund's coupling
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Electronic correlations, magnetism and Hund's rule coupling in the ruthenium perovskites SrRuO${}_3$ and CaRuO${}_3$
• A Novel Pyrochlore Ruthenate: Ca2Ru2O7
• Nonlocal correlations induced by Hund's coupling: a cluster DMFT study
• Itinerant ferromagnetism in the multiorbital Hubbard model: a dynamical mean-field study
• Studies of the Anomalous Hall Effect and Magnetic Structure of Nd2Mo2O7 -Test of the Chirality Mechanism-

Cited by in corpus (3)

• Magnetic structures and electronic properties of cubic-pyrochlore ruthenates from first principles
• Metal-insulator transitions in pyrochlore oxides
• Geometrical frustration and incommensurate magnetic order in Na${}_3$RuO${}_4$ with two triangular motifs