Evolution of Magneto-Orbital order Upon B-Site Electron Doping in Na<sub>1−x</sub>Ca<sub>x</sub>Mn<sub>7</sub>O<sub>12</sub> Quadruple Perovskite Manganites

ORAL

Abstract

We present the discovery and refinement by neutron powder diffraction of a new magnetic phase in the Na1−xCaxMn7O12 quadruple perovskite phase diagram, which is the incommensurate analogue of the well known pseudo-CE phase of the simple perovskite manganites. We demonstrate that incommensurate magnetic order arises in quadruple perovskites due to the exchange interactions between A and B sites. Furthermore, by constructing a simple mean field Heisenberg exchange model that generically describes both simple and quadruple perovskite systems, we show that this new magnetic phase unifies a picture of the interplay between charge, magnetic, and orbital ordering across a wide range of compounds.

*We acknowledge financial support from the Royal Society (UK) and from EPSRC (UK), Grant No. EP/M020517/1, entitled “Oxford Quantum Materials Platform Grant.”

–

Presenters

  • Roger Johnson

    • University of Oxford
    • ISIS Pulsed Neutron Source, Rutherford Appleton Laboratory
    • Clarendon Laboratory, University of Oxford
    • Department of Physics, University of Oxford
    • Physics, University of Oxford

Authors

  • Roger Johnson

    • University of Oxford
    • ISIS Pulsed Neutron Source, Rutherford Appleton Laboratory
    • Clarendon Laboratory, University of Oxford
    • Department of Physics, University of Oxford
    • Physics, University of Oxford

  • Francesco Mezzadri

    • Istituto dei Materiali per Elettronica e Magnetismo

  • Pascal Manuel

    • ISIS Pulsed Neutron Source, Rutherford Appleton Laboratory
    • ISIS Facility, STFC

  • Dmitry Khalyavin

    • ISIS Neutron and Muon Source Science and Technology Facilities Council
    • ISIS, Rutherford Appleton Laboratory
    • ISIS Facility, STFC

  • Edmondo Gilioli

    • Istituto dei Materiali per Elettronica e Magnetismo

  • Paolo G. Radaelli

    • Physics, University of Oxford
    • Clarendon Laboratory, University of Oxford
    • University of Oxford