Structure-property relations in multiferroic [CH<sub>3</sub>)<sub>2</sub>NH<sub>2</sub>]<i>M</i>(HCOO)<sub>3</sub> (<i>M</i>=Mn,Co,Ni)

ORAL

Abstract

We combine magnetization and infrared spectroscopy to unveil the B-T phase diagrams and vibrational properties of the [(CH3)2NH2]M(HCOO)3 (M=Mn,Co,Ni) family of multiferroics. While the magnetically-driven transition to BC in the Mn analog takes place at 15.3 T, much higher fields are required to saturate the Ni and Co materials. Analysis of the infrared spectrum of the Mn and Ni compounds across TC reveals splitting of the formate bending mode which functions as an order parameter of the ferroelectric transition. By contrast, the Co complex reveals a surprising framework rigidity where the ferroelectric state is driven solely by counterion freezing. With magnetic field, the Mn (and most likely, the Ni) materials engage the formate bending mode to facilitate the transition to the fully saturated magnetic states, whereas the Co complex adopts an alternate mechanism involving formate stretching distortions. Similar structure-property relations involving substitution of transition metal centers and control of the flexible molecular architecture are likely to exist in other molecule-based multiferroics.

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Presenters

  • Kendall Hughey

    • University of Tennessee

Authors

  • Kendall Hughey

    • University of Tennessee

  • Amanda Clune

    • University of Tennessee

  • Michael O Yokosuk

    • University of Tennessee

  • Jing Li

    • Fudan University

  • Nandita Abhyankar

    • Florida State University

  • Xiaxin Ding

    • Idaho National Laboratory
    • National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • Los Alamos National Laboratory

  • Naresh Dalal

    • Florida State University

  • Hongjun Xiang

    • Physics Department, Fudan University
    • Fudan University

  • Dmitry Smirnov

    • National High Magnetic Field Laboratory
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Lab
    • Condensed Matter Science, National High Magnetic Field Laboratory

  • John Singleton

    • National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • MPA-MAG, Los Alamos National Laboratory
    • National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545
    • Los Alamos National Laboratory
    • NHMFL, Los Alamos National Labs
    • NHMFL, Los Alamos National Laboratory
    • Los Alamos, National High Magnetic Field Laboratory
    • NHMFL, Los Alamos Natl Lab
    • Los Alamos Natl Lab

  • Janice Lynn Musfeldt

    • Univ of Tennessee, Knoxville
    • Department of Physics and Astronomy, Department of Chemistry, University of Tennessee
    • University of Tennessee