Properties of the Predicted Multiferroic Ca$_{3}$Mn$_{2}$O$_{7}$ - Experiment

ORAL

Abstract

We have studied the properties of epitaxial films of Ca$_{3}$Mn$_{2}$O$_{7}$, an $n=2$ Ruddlesden-Popper phase. This material has been predicted to have novel multiferroic properties, including electric field switching of the magnetization [1]. 50 nm thick unstrained Ca$_{3}$Mn$_{2}$O$_{7}$ films were grown by reactive MBE on (110) YAlO$_{3}$ single crystal substrates. XRD shows that the Ca$_{3}$Mn$_{2}$O$_{7}$ films are single phase and epitaxial with (001) Ca$_{3}$Mn$_{2}$O$_{7}$ // (110) YAlO$_{3}$. Our films show a transition to a weakly ferromagnetic or canted antiferromagnetic state below 120K. The magnetic properties have strong anisotropy with a clear transition visible with an in-plane applied field, but none along the out of plane direction. Second harmonic generation results show that a weak polar order exists at room temperature and it persists until $\sim $700$^{\circ}$C. We also report on the low temperature dielectric properties of the material. \\[4pt] [1] N. A. Benedek and C. J. Fennie, arXiv:1007.1003v1.

–

Authors

  • R. Misra

    The Pennsylvania State University, University Park, PA

  • Carolina Adamo

    Cornell University, NY, Cornell University

  • Nicole Benedek

    Cornell University, NY, School of Applied and Engineering Physics, Cornell University, Cornell University

  • Sava Denev

    The Pennsylvania State University, The Pennsylvania State University, University Park, PA, Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • A. SenGupta

    The Pennsylvania State University, University Park, PA

  • J.A. Mundy

    Cornell University, NY

  • J.H. Lee

    The Pennsylvania State University, University Park, PA

  • D.A. Muller

    Cornell University, NY

  • Venkatraman Gopalan

    The Pennsylvania State University, The Pennsylvania State University, University Park, PA, Pennsylvania State University, Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Craig Fennie

    Cornell University, Cornell University, NY, School of Applied and Engineering Physics, Cornell University, School of Applied and Engineering Physics, Cornell University, Ithaca, NY

  • Darrell Schlom

    Cornell University, Cornell University, NY

  • Peter Schiffer

    The Pennsylvania State University, University Park, PA, Pennsylvania State University, Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA, Department of Physics and Materials Research Institute, Pennsylvania State University, University Park, PA 16802, Penn State University