Two isostructural layered oxohalide compounds containing Mn2+, Te4+ and Si4+; crystal structure and magnetic susceptibility
2014 (English)In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 218, 6-9 p.Article in journal (Refereed) Published
The new compounds Mn-4(TeO3)(SiO4)X-2 (X=Br, Cl) were synthesized by solid state reactions in sealed evacuated silica tubes. The compounds crystallize in the monoclinic space group P2(1)/m with the unit cell parameters a=5.5463(3) angstrom (5.49434(7) angstrom), b= 6.4893(4) angstrom (6.44184(9) angstrom), c=12.8709(7) A (12.60451 (18) angstrom), beta=93.559(5)degrees (94.1590(12)degrees) and Z=2 for the respective Br and Cl analogues. Manganese adopts various distorted coordination polyhedra; [MnO6] octahedra, [MnO5] tetragonal pyramids and [MnO2X2] tetrahedra. Other building blocks are [SiO4] tetrahedra and [TeO3] trigonal pyramids. The structure is made up from layers having no net charge that are connected via weak Van der Waal interactions. The layers that are parallel to (1 1 0) consist of two manganese oxide sheets which are separated by [Siad tetrahedra. On the outer sides of the sheets are the [MnO2X2] tetrahedra and the [TeO3] trigonal pyramids connected so that the halide ions and the stereochemically active lone pairs on the tellurium atoms protrude from the layers. Magnetic susceptibility measurements reveal a Curie law with a Weiss temperature of theta=-153(3) K for temperatures >= 100 K and indicate antiferromagnetic ordering at TN similar to 4 K. Possible structural origins of the large frustration parameter of f=38 are discussed.
Place, publisher, year, edition, pages
2014. Vol. 218, 6-9 p.
Oxohalide, Layered compounds, Crystal structure, Magnetic susceptibility
Research subject Inorganic Chemistry
IdentifiersURN: urn:nbn:se:su:diva-107092DOI: 10.1016/j.jssc.2014.05.027ISI: 000339987000002OAI: oai:DiVA.org:su-107092DiVA: diva2:743974