New metal-rich mixed chalcogenides with intergrowth structures: Ni8.21Ge2S2 and Ni8.45Ge2Se2
2009 (English)In: Solid State Sciences, ISSN 1293-2558, Vol. 11, no 6, 1071-1076 p.Article in journal (Refereed) Published
New metal-rich mixed nickel germanium chalcogenides, Ni8.21(1)Ge2S2 and Ni8.45(1)Ge2Se2, were synthesized by a high-temperature ceramic technique. Ni8.21Ge2S2 decomposes incongruently at 798(5) degrees C, while Ni8.45Ge2Se2 is stable only between approximately 600(5) degrees C and 813(5) degrees C. Single crystals were grown from a molten flux and by a recrystallization of presynthesized charge. The X-ray diffraction study revealed that Ni8.21Ge2S2 and Ni8.45Ge2S2 are isostructural and crystallize in the tetragonal system (space group 14/mmm, Z = 2) with a = 3.578(1) angstrom, c = 24.687(5) angstrom, and a = 3.601 (1) angstrom, c = 25.427(6) angstrom, respectively. Their crystal structures comprise heterometallic (2)(infinity) [Ni6Ge2] slabs and are closely related to the Ni8.54Ga2Se2 and Ni8.93Sn2S2 structure types. The geometrical changes of structural units upon p-element substitution in all known Ni(10-delta)E(2)Q(2) (E = element of group 13 or 14; Q = chalcogen) compounds are discussed. The relation to the intergrowth structure of Ni5.46GeSe2 is analyzed.
Place, publisher, year, edition, pages
2009. Vol. 11, no 6, 1071-1076 p.
IdentifiersURN: urn:nbn:se:kth:diva-18554DOI: 10.1016/j.solidstatesciences.2009.03.005ISI: 000267498700003ScopusID: 2-s2.0-67349088810OAI: oai:DiVA.org:kth-18554DiVA: diva2:336601
QC 201005252010-08-052010-08-052011-02-09Bibliographically approved