39332-13-3Relevant articles and documents
Synthesis, crystal structure, and thermoelectric properties of clathrates in the Sn-In-As-I system
Kelm, Evgeny A.,Olenev, Andrei V.,Bykov, Mikhail A.,Sobolev, Alexey V.,Presniakov, Igor A.,Kulbachinskii, Vladimir A.,Kytin, Vladimir G.,Shevelkov, Andrei V.
, p. 2059 - 2067 (2011)
Clathrates of the general formula Sn24-x- γInxAs22-yI8 have been synthesized with xmax = 10.7. They crystallize in the clathrate-I type of crystal structure, space group Pmβar{3}ν, with the cubic unit cell parameter ranging from a = 11.088 (x = 0) to a = 11.343 (x = 10.7) A. The crystal structure refined for five compositions with different indium contents revealed that despite the linear dependence of the unit cell parameter upon x the details of the crystal structure change twice upon varying the indium contents. These changes occur without altering the space group and show up in positional disorder of atoms within the framework and the concomitant change of the coordination of part of tin atoms from 3+2 to 3+3, which is additionally confirmed by the Moessbauer spectroscopy data. In general, these changes reflect the transition from the Sn24P 19.3I8 structure type for high indium contents to the Sn20.5As22I8 structure type for low indium contents. It is shown that the Sn24-x-γIn xAs22-yI8 clathrates have n-type conductivity with high values of the Seebeck coefficient ranging from -322 to -594 γVA·K-1 at room temperature. They display an abnormally low thermal conductivity at 293 K, from 0.36 to 0.57 WA·m-1A·K-1. The calculated thermoelectric figure-of-merit for Sn24-x-γIn xAs22-yI8 has its room-temperature maximum at 0.041 for x = 6.5. Copyright
Sn4As3 revisited: Solvothermal synthesis and crystal and electronic structure
Kovnir, Kirill,Kolen'ko, Yury V.,Baranov, Alexey I.,Neira, Ines S.,Sobolev, Alexey V.,Yoshimura, Masahiro,Presniakov, Igor A.,Shevelkov, Andrei V.
, p. 630 - 639 (2009)
A facile one pot method of synthesis of tin arsenide Sn4As3 starting from metallic tin and elemental arsenic under mild solvothermal conditions in ethylenediamine in the presence of ammonium chloride is offered. The dissolving of the
SnAs: A 4K weak type-II superconductor with non-trivial band topology
Sharma,Karn,Sharma, Prince,Gurjar, Ganesh,Patnaik,Awana
, (2021/09/30)
Superconductors with non-trivial band topology are emerging as one of the best avenues to study quantum anomalies and experimental realization of Majorana Fermions. This article reports the successful crystal growth of superconducting SnAs, which can have topologically non-trivial states, as evidenced in DFT (Density Functional Theory) calculations, Z2 invariants and topological surface states. Here, we followed a two-step method to grow SnAs crystal. The powder XRD (X-ray Diffractometry) pattern of synthesized crystal ensures that the crystal is grown in a single phase with a NaCl type cubic structure and the EDAX (Energy Dispersive X-ray Analysis) endorses the stoichiometry of the as-grown sample. The DFT calculations performed with and without inclusion of spin-orbit coupling (SOC) show band inversion at various k symmetry points near the Fermi level. The recorded Raman spectra show two different modes, which are assigned as A1 and ETO vibrations. The ZFC (Zero-Field Cooled) & FC (Field Cooled), as well as the isothermal M ? H (Magnetization vs. field) measurements, are also performed for the topological non-trivial SnAs superconductor, which eventually confirm the weak type-II superconductivity at 4K. Various other superconductivity parameters viz. kappa parameter, coherence length, and penetration depth are also calculated to probe the as-grown sample's characteristics.
