Magnetic superstructures inside the ⅓ and ½ magnetization plateaux in Ba2CoTeO6 revealed by magnetostriction and magnetocaloric effect measurements

ORAL

Abstract

Ba2CoTeO6 is composed of two nearly decoupled magnetic spin-systems stacked as alternating 2D layers along the crystallographic c-direction in the trigonal crystal structure. Subsystem A is a S = ½ triangular Heisenberg antiferromagnet that orders at TA = 3K. System B is a J1-J2 honeycomb Ising antiferromagnet with ordering temperature TB = 12K. Both underlying spin-models are interesting due to geometrical frustration (A) and bond frustration (B) causing magnetic plateaux upon the application of magnetic fields H. We present a combination of magnetostriction and magnetocaloric effect (MCE) measurements in high pulsed and static magnetic fields to map out the phase diagram for H ll and perp. to the A and B layers. We observe distinct anomalies in the sample length ΔL/L as a function of field and temperature indicating phase transitions as well as signatures in the MCE measurement indicating a change of entropy. These anomalies are accompanied by significant hysteresis in decreasing compared to increasing magnetic fields.

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Presenters

  • Dagmar Weickert

    National High Magnetic Field Laboratory, Florida State University

Authors

  • Dagmar Weickert

    National High Magnetic Field Laboratory, Florida State University

  • Carolina Corvalan-Moya

    CONICET, NCNEA-UNTREF

  • Myron B Salamon

    University of Texas at Dallas, Los Alamos National Laboratory, NHMFL-LANL

  • Chao Dong

    ISSP, Tokyo University

  • Koichi Kindo

    ISSP, Tokyo University, University of Tokyo

  • Yoshimitsu Kohama

    ISSP, Tokyo University, The Institute for Solid State Physics, University of Tokyo, Institute for Solid State Physics, University of Tokyo, The Institute for Solid State Physics, The University of Tokyo

  • Nobuyuki Kurita

    Tokyo Tech

  • Hidekazu Tanaka

    Tokyo Tech, Department of Physics, Tokyo Institute of Technology