Serebryanaya N.,Technological Institute for Superhard and Novel Carbon MaterialsCentralnaya Street 7a142190Troitsk |
Tatyanin E.,Technological Institute for Superhard and Novel Carbon MaterialsCentralnaya Street 7a142190Troitsk |
Buga S.,Technological Institute for Superhard and Novel Carbon MaterialsCentralnaya Street 7a142190Troitsk |
Kruglov I.,Moscow Institute Of Physics And Technologyinstitutskiy Per 9141700Dolgoprudny |
And 2 more authors.
Physica Status Solidi (B) Basic Research | Year: 2014
We synthesized metastable phases of Sb2Te3 and Bi0.4Sb1.6Te3 by quenching after high-pressure (4GPa) and high-temperature (873K) treatment and specify them as m-Sb2Te3 and m-Bi0.4Sb1.6Te3. The metastable phases of both alloys crystallize in the same structure type. The crystal structure of metastable phases, determined by the powder X-ray and electron diffraction methods, is monoclinic (C2/m). The cell dimensions of m-Sb2Te3 are: a=15.644(80) Å, b=4.282(8) Å, c=9.382(20) Å, β=89.70(5)°, the cell dimensions of m-Bi0.4Sb1.6Te3 diverge by a hundredth of angstrom units and monoclinic angle - by tenths of a degree. We revealed that the structure of β-Sb2Te3-phase, observed in situ under high pressure, may be represented as a structure of m-Sb2Te3-type and thus it can be retained at ambient conditions. We investigated the temperature dependencies of the electrical resistivity and the Hall coefficient of recovered samples in the range of T=1.8-450K. The structure of metastable phases possesses metallic type bonding and m-Sb2Te3 phase is superconductive at T<2K. The ab initio study verified metallic character of the quenched phases. After annealing at 673K during 2.5h the structures of the recovered samples Sb2Te3 and Bi0.4Sb1.6Te3 returned to initial rhombohedral symmetry. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.