Synthesis, structure and geometrically frustrated magnetism of the layered oxide-stannide compounds Fe(Fe3−xMnx)Si2Sn7O16. Issue 23 (26th May 2016)

• Record Type: Journal Article
• Authors: Allison, M. C.; Avdeev, M.; Schmid, S.; Liu, S.; Söhnel, T.; Ling, C. D.
• Is Part Of: Dalton transactions. Volume 45:Issue 23(2016)
• Page Start: 9689
• Page End: 9694
• Publication Date: 2016-05-26
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c6dt01074a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Fe4 Si2 Sn7 O16 has a unique crystal structure that contains alternating layers of Fe 2+ ions octahedrally coordinated by O (oxide layer) and Sn (stannide layer), bridged by SiO4 tetrahedra. Abstract : Fe4 Si2 Sn7 O16 has a unique crystal structure that contains alternating layers of Fe 2+ ions octahedrally coordinated by O (oxide layer) and Sn (stannide layer), bridged by SiO4 tetrahedra. The formula can be written as FeFe3 Si2 Sn7 O16 to emphasise the distinction between the layers. Here, we report the changes in structure and properties as iron is selectively replaced by manganese in the oxide layer. Solid-state synthesis was used to produce polycrystalline samples of Fe(Fe3− x Mn x )Si2 Sn7 O16 for x ≤ 2.55, the structures of which were characterised using high-resolution synchrotron X-ray and neutron powder diffraction. Single-crystal samples were also grown at x = 0.35, 0.95, 2.60 and characterised by single crystal X-ray diffraction. We show that manganese is doped exclusively into the oxide layer, and that this layer contains exclusively magnetically active high-spin M 2+ transition metal cations; while the stannide layer only accommodates non-magnetic low-spin Fe 2+ . All samples show clear evidence of geometrically frustrated magnetism, which we associate with the fact that the topology of the high-spin M 2+ ions in the oxide layer describes a perfect kagomé lattice. Despite this frustration, the x = 0 and x = 2.55 samples undergo long-range antiferromagnetic ordering transitions at 3.0 K and 2.5 K, respectively.