Investigation of the Jahn-Teller transition in La1-xSrxMnO3 by single-crystal neutron diffuse scattering

ORAL

Abstract

The Jahn-Teller (JT) distortion occurs in a single valance system where a structural distortion is needed to lift the orbital degeneracy. In the mixed valance system La1-xSrxMnO3 (LSMO), the JT transition remains robust and sharp. It is not clear if the distribution of Mn3+ in Mn4+ matrix plays an important role. On cooling, LSMO undergoes the cooperative JT transition to order orbitals, spin ordering transition, and the charge ordering transition[1]. Pair distribution function analysis of neutron powder diffraction data has previously been done to discuss the role of polarons in the transition[2,3]. With single-crystal neutron diffuse scattering (NDS), we have observed patterns that show an interesting evolution as it is cooled through three transitions. Weak rod-shaped NDS features along L with even H+K above TJT get enhanced as the temperature is cooled below TJT, suggesting coherent scattering is developed above TJT. The NDS features disappear below the charge ordering transition temperature TCO, associated with the formation of superlattices. Potential models to interpret the observations will be discussed.
[1] Phys. Rev. B 91, 064414 (2015)
[2] Phys. Rev. Lett. 77, 715 (1996)
[3] Phys. Rev. B 56, R8475 (1997)

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Presenters

  • Hongze Li

    Walker Department of Mechanical Engineering, University of Texas at Austin

Authors

  • Hongze Li

    Walker Department of Mechanical Engineering, University of Texas at Austin

  • Yaohua Liu

    Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge National Lab, Oak Ridge National Laboratory

  • Jianshi Zhou

    Geological Sciences, University of Texas at Austin, Department of Mechanical Engineering, The University of Texas at Austin, Walker Department of Mechanical Engineering, University of Texas at Austin, Department of Mechanical Engineering, University of Texas at Austin, The University of Texas at Austin, University of Texas at Austin, University of Texas, Materials Science and Engineering program, Department of Mechanical Engineering, University of Texas at Austin