Magnetic phase diagram of (Sr$_{1-x}$Ca$_{x})_{3}$Ru$_{2}$O$_{7 }$ (0$\le $x$\le $1.0)

ORAL

Abstract

The layered ruthenates (Sr,Ca)$_{n+1}$Ru$_{n}$O$_{3n+1}$ have received widespread attention in recent years since they display a remarkable range of unique superconducting and magnetic properties, such as spin triplet superconductivity and metamagnetic quantum criticality. We have recently studied properties of the double layered (Sr$_{1-x}$Ca$_{x})_{3}$Ru$_{2}$O$_{7}$ solid solution series and established the magnetic phase diagram of this system using the high-quality single crystals grown by floating-zone method. We have observed rich magnetic ground states in this system: (I) Itinerant metamagnetic state (0.08$>x\ge $0); (II) enhanced PM state accompanied by non-Fermi liquid behaviors near $x\sim $0.08; (III) ferromagnetic cluster glass (CG) phase featuring an extremely large Wilson ratio ($\sim $120) and enhanced electron correlation (0.40$>x>$0.08); (IV) long-range AFM state (1$\ge x\ge $0.40). Furthermore, we found a new phase which shows an unconventional anomalous Hall effect in a low temperature range immediately above the CG phase. The magnetization of this phase is found to follow a new scaling expression derived by phenomenologically extending the quantum Griffiths phase model.

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Authors

  • Z.Q. Mao

    Tulane University, USA, TU, Tulane University (TU)

  • Z. Qu

    TU

  • Leonard Spinu

    Department of Physics \& Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, USA, University of New Orleans, AMRI, University of New Orleans, Univ. of New Orleans Dept. of Physics \& AMRI

  • J. Peng

    Tulane University (TU), TU

  • T.J. Liu

    TU

  • D. Fobes

    Tulane University, USA, TU

  • Vladimir Dobrosavljevic

    NHMFL and Florida State University, Florida State University

  • Huiqiu Yuan

    Los Alamos National Laboratory

  • W. Bao

    Los Alamos National Lab., Los Alamos National Laboratory

  • J. W. Lynn

    National Institute of Standards and Technology, NIST Center for Neutron Scattering, NIST, NCNR, National Institute of Standards and Technology, Gaithersburg, MD 20899, NCNR, National Institute of Standards and Technology