Abstract
A new family of anhydrous sulfates, A2+Mn5(SO4)6 (A=Pb, Ba, Sr) is reported. The crystal structures of PbMn5(SO4)6 and SrMn5(SO4)6 are solved by powder X-ray and neutron diffraction. BaMn5(SO4)6 is isostructural. PbMn5(SO4)6 crystallizes with P over(3, -) symmetry and unit cell parameters of a=14.551(1) Å and c=7.535(1) Å. The structure has rich features, including dimers of face-sharing MnO6 octahedra, and two complementary triangular layers of Mn atoms. All compounds undergo a magnetic ordering transition at 10 K, below which, the magnetic susceptibility of the compounds varies systematically with the radius of the non-magnetic cation. Low temperature neutron diffraction shows that the complementary triangular layers result in a ferrimagnet with a net moment corresponding to one high spin Mn2+ per unit cell, correlating well with the magnetization data. The non-magnetic variant PbMg5(SO4)6 is also reported.
Original language | English (US) |
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Pages (from-to) | 1343-1350 |
Number of pages | 8 |
Journal | Journal of Solid State Chemistry |
Volume | 182 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2009 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry
Keywords
- Crystallography
- Geometric frustration
- Magnetism
- New crystal structure
- Regular polygon tiling
- Sulfate
- Triangular lattice