Nowotny Chimney Ladder Phases with Group 5 Metals: Crystal and Electronic Structure and Relations to the CrSi2 Structure Type

Autor: Maxim S. Likhanov, Nikita V. Sytov, Zheng Wei, Evgeny V. Dikarev, Andrei V. Shevelkov
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Crystals, Vol 10, Iss 8, p 670 (2020)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst10080670
Popis: Nowotny chimney ladder (NCL) phases are intermetallic compounds formed by transition metals and metals of groups 13 and 14. This family can be expanded by combining two p-elements from different groups with those transition metals, for which the corresponding binary NCL phases are unknown. In this paper, we present three new compounds in the V-Al-Ge, Nb-Al-Ge, and Nb-Ga-Ge systems related to the TiSi2 structure type (Sp. Gr. Fddd) obtained with the standard ampule technique. The crystal structures of the new compounds were determined using synchrotron powder X-ray diffraction data. A transition to the CrSi2 structure type was detected upon changing the composition from VAl0.72(2)Ge1.28(2) to VAl1.534(3)Ge0.466(3). According to the 18–n rule, all the compounds are metallic conductors, which was supported by the electronic structure calculations. It was shown that the expected energy gap located above the Fermi level in the vanadium-based NCL compound collapsed into a pseudogap upon the replacement of V by Nb.
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