Ferromagnetism and Charge Order from a Frozen Electron Configuration in Strained Epitaxial ${\mathrm{LaCoO}}_{3}$

Ferromagnetism and Charge Order from a Frozen Electron Configuration in Strained Epitaxial ${LaCoO}_{3}$

G. E. Sterbinsky, R. Nanguneri, J. X. Ma, J. Shi, E. Karapetrova, J. C. Woicik, H. Park, J.-W. Kim, and P. J. Ryan

Phys. Rev. Lett. 120, 197201 – Published 8 May 2018

Abstract

We report ordering of the cobalt electron configuration in ferromagnetic strained epitaxial ${LaCoO}_{3}$ . Specifically, the presence of charge order is demonstrated from distinct features of the resonant cobalt contribution to superstructure reflections. Density functional theory calculations show that the observed order is consistent with the spin-state periodicity predicted to give rise to ferromagnetism in ${LaCoO}_{3}$ . Through the modification of symmetry by strain, concurrent frozen charge and spin-state order are stabilized, giving rise to long-range magnetic order.

Received 17 January 2017
Revised 8 March 2018

DOI:https://doi.org/10.1103/PhysRevLett.120.197201

Physics Subject Headings (PhySH)

Ferromagnetism

Density functional theory Resonant elastic x-ray scattering

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

G. E. Sterbinsky^1,*, R. Nanguneri², J. X. Ma³, J. Shi³, E. Karapetrova¹, J. C. Woicik⁴, H. Park^2,5, J.-W. Kim¹, and P. J. Ryan^1,6

¹Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
²Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA
³Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
⁴National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
⁵Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
⁶School of Physical Sciences, Dublin City University, Dublin 9, Ireland