ic7b01269_si_001.pdf (212.88 kB)
Mn2TeO6: a Distorted Inverse Trirutile Structure
journal contribution
posted on 2017-08-07, 16:17 authored by Nami Matsubara, Françoise Damay, Bénédicte Vertruyen, Nicolas Barrier, Oleg I. Lebedev, Philippe Boullay, Erik Elkaïm, Pascal Manuel, Dmitry D. Khalyavin, Christine MartinInverse trirutile Mn2TeO6 was investigated using in situ neutron and X-ray powder diffraction
between 700 °C and room temperature. When the temperature was
decreased, a structural phase transition was observed around 400 °C,
from a tetragonal (P42/mnm) to a monoclinic phase (P21/c), involving a doubling of the cell parameter along b. This complex monoclinic structure has been solved by
combining electron, neutron, and synchrotron powder diffraction techniques
at room temperature. It can be described as a distorted superstructure
of the inverse trirutile structure, in which compressed and elongated
MnO6 octahedra alternate with more regular TeO6 octahedra, forming a herringbone-like pattern. Rietveld refinements,
carried out with symmetry-adapted modes, show that the structural
transition, arguably of Jahn–Teller origin, is driven by a
single primary mode.