T-P phase diagram for the new local moment 4f ferromagnet CeRu$_{2}$Ga$_{2}$B

ORAL

Abstract

We will report results for single crystals of a new Ce-based local moment ferromagnet, CeRu$_{2}$Ga$_{2}$B. Electrical resistivity, magnetization, and magnetic susceptibility measurements reveal ferromagnetism and hysteresis around T$_{C}$ = 16.1 K, while specific heat measurements uncover a huge anomaly at the phase transition, which results in a large discontinuity in the magnetic entropy ($\Delta $S$_{mag }$= 1.7 J/mol-K). Taken together, these data show that CeRu$_{2}$Ga$_{2}$B undergoes a first order ferromagnetic phase transition at a surprisingly high temperature. Since this type of behavior is unusual for Ce-based compounds, we additionally undertook an effort to tune the magnetic state using pressure. We will present electrical resistivity measurements under applied pressures and the resulting temperature-pressure phase diagram, with an emphasis on implications for possible nearness to a ferromagnetic quantum critical point.

Authors

  • E.D. Bauer

    Los Alamos National Laboratory, Los Alamos National Lab

  • Ryan E. Baumbach

    Los Alamos National Laboratory, University of California at San Diego

  • X. Lu

    Los Alamos National Lab, Los Alamos National Laboratory

  • T. Shang

    Los Alamos National Laboratory

  • F. Ronning

    Los Alamos National Lab, Los Alamos National Laboratory, Los Alamos National Laboratory, Los Alamos, NM

  • J.D. Thompson

    LANL, Los Alamos National Lab, Los Alamos National Laboratory

  • C.H. Wang

    Oak Ridge National Laboratory

  • V.O. Garlea

    Oak Ridge National Laboratory, ORNL, Neutron Scattering Science Division, Oak Ridge National Laboratory, Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831

  • A.D. Christianson

    ORNL, Oak Ridge National Laboratory