Fizika Nizkikh Temperatur: Volume 45, Number 2 (February 2019), p. 278-282    ( to contents , go back )

Electronic transport and optical properties of Mo0.5W0.5Te2 single crystal

V.V. Marchenkov1,2, A.N. Domozhirova1, A.A. Makhnev1, E.I. Shreder1, S.V. Naumov1, V.V. Chistyakov1, J.C.A. Huang3, and M. Eisterer4

1M.N. Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences Yekaterinburg 620108, Russia
E-mail: domozhirova@imp.uran.ru

2Ural Federal University, Ekaterinburg, Russia

3National Cheng Kung University, University Road, 1, Tainan 70101, Taiwan

4TU Wien Atominstitut, Stadionallee, 2, Vienna 1020, Austria

Received December 4, 2018, published online December 20, 2018

Abstract

A relatively pure and perfect Weil semimetal Mo0.5W0.5Te2 single crystal was synthesized and its electrical resistivity, galvanomagnetic properties at temperatures from 4.2 to 80 K in magnetic fields up to 10 T and also optical properties at room temperature were studied. It is shown that the temperature de-pendence of the resistivity has a metallic type. At T = 4.2 K and in a field of 10 T, the magnetoresistivity reaches 29%, monoto-nously decreasing with temperature. Analysis of the field and temperature dependences of the magnetoresistivity suggests that the Fermi surface of the Mo0.5W0.5Te2 can contain both open and closed sheets. Studies of the Hall effect and estimates made on this basis showed that the majority carriers are electrons with a concentration of ~ 1020 cm–3 and mobility of ~ 151 cm2/V·s at T = 4.2 K. Concentration of current carriers increases with temperature, and mobility decreases. Optical studies showed that the Mo0.5W0.5Te2 single crystal does not exhibit features characteristic of metals. Interband absorption of light dominates over the entire studied range of the spectrum. The appearance of a weak contribution from free carriers is noted at energies of less than 0.6 eV.

Key words: topological Weyl semimetals, transition metal dichalcogenides, single crystals, electrical resistivity, galvano-magnetic properties, optical properties.

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