Crystal structure and monoclinic distortion of glaserite-type Ba3MnSi2O8
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ArticleAbstract
Crystal structure and magnetic properties of glaserite-type Ba3MnSi2O8 were investigated using variable temperature neutron powder diffraction and magnetometry. At room temperature the composition is hexagonal and the crystal structure is best described by the P-3m1 space group ...
See moreCrystal structure and magnetic properties of glaserite-type Ba3MnSi2O8 were investigated using variable temperature neutron powder diffraction and magnetometry. At room temperature the composition is hexagonal and the crystal structure is best described by the P-3m1 space group (a~5.7 Å, c~7.3Å) with the apical oxygen atom modelled on a split site. On cooling below ~250 K the structure undergoes a phase transition into a monoclinic C2/c form (√3ahex, ahex, 2chex, ~90°). Analysing diffraction data in terms of symmetry-adapted distortion modes suggests that the transition is primarily driven by increasing in-plane displacements of O1, which in turn results in the coupled tilting of [SiO4] and [MnO6] octahedra and in- plane displacements of Ba1 atoms. Magnetic susceptibility measurements and neutron powder diffraction data show no evidence for long-range magnetic ordering down to 1.6 K, although the development of magnetic diffuse scattering suggests that a magnetic transition may take place at lower temperature.
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See moreCrystal structure and magnetic properties of glaserite-type Ba3MnSi2O8 were investigated using variable temperature neutron powder diffraction and magnetometry. At room temperature the composition is hexagonal and the crystal structure is best described by the P-3m1 space group (a~5.7 Å, c~7.3Å) with the apical oxygen atom modelled on a split site. On cooling below ~250 K the structure undergoes a phase transition into a monoclinic C2/c form (√3ahex, ahex, 2chex, ~90°). Analysing diffraction data in terms of symmetry-adapted distortion modes suggests that the transition is primarily driven by increasing in-plane displacements of O1, which in turn results in the coupled tilting of [SiO4] and [MnO6] octahedra and in- plane displacements of Ba1 atoms. Magnetic susceptibility measurements and neutron powder diffraction data show no evidence for long-range magnetic ordering down to 1.6 K, although the development of magnetic diffuse scattering suggests that a magnetic transition may take place at lower temperature.
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Date
2018Source title
Journal of Solid State ChemistryVolume
266Publisher
ElsevierFunding information
ARC DP170100269Licence
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0Rights statement
© This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Faculty/School
Faculty of Science, School of ChemistryShare