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An annealing study of CaMn<sub>2</sub>O<sub>4-</sub><sub>d</sub>, a possible multiferroic candidate

ORAL

Abstract

Manganese oxides have experienced a considerable increase in research interest due to their rich and complex phase diagrams. Ca-Mn-O is an excellent example, whose rich phase diagram contains phases that have been theoretically predicted to be multiferroic and CaMn2O4 to date is still not well understood and a hopeful candidate. Polycrystalline samples were synthesized and annealed with two different growth environments to further investigate the effect of oxygen deficiencies. Therefore, argon as well as oxygen gas flows were utilized. From initial dc magnetization and Cp measurements, the previously report TN ~ 220 K was observed for both samples. However, a spontaneous polarization (PS) was observed at ~ 253 K for the oxygen annealed sample with no applied field while no PS was observed up to 7 T and temperatures down to 2 K for the argon annealed sample. Anomalies above 260 K were detected in both samples, which were not only time-, but also field-dependent. Measurements are ongoing to gain greater insight into this complex system.

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Presenters

  • Melissa Gooch

    Texas Center for Superconductivity, Univ of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA, Texas Center for Superconductivity, University of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Texas Center for Superconductivity, University of Houston, Texas

Authors

  • Melissa Gooch

    Texas Center for Superconductivity, Univ of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA, Texas Center for Superconductivity, University of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Texas Center for Superconductivity, University of Houston, Texas

  • Hung-Cheng Wu

    Physics, National Sun Yat-sen University, Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA, Texas Center for Superconductivity, University of Houston, Department of Physics, National Sun Yat-sen University, Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan, Natl Sun Yat Sen Univ, Texas Center for Superconductivity and Physics Department at the Univ of Houston

  • Liangzi Deng

    Texas Center for Superconductivity, Univ of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA, Texas Center for Superconductivity, University of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Texas Center for Superconductivity, University of Houston, Texas, 77204, USA, Texas Center for Superconductivity and Physics Department at the Univ of Houston

  • Hung-Duen Yang

    Physics, National Sun Yat-sen University, Department of Physics, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan, Department of Physics, National Sun Yat-sen University, Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan, Natl Sun Yat Sen Univ, Department of Physics, National Sun Yat-sen University, Taiwan

  • Paul C. W. Chu

    Texas Center for Superconductivity, Univ of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA, Texas Center for Superconductivity, University of Houston, Texas Center for Superconductivity and Department of Physics, University of Houston, Texas Center for Superconductivity and Physics Department at the Univ of Houston