Low Temperature Physics: 43, 257 (2017); https://doi.org/10.1063/1.4977587
Fizika Nizkikh Temperatur: Volume 43, Number 2 (February 2017), p. 313-321    ( to contents , go back )

Lifshitz topological transitions induced by doping and deformation in single-crystal Bi wires

A.A. Nikolaeva1,2, L.A. Konopko1,2, T.E. Huber3, A.K. Kobylianskaya1, and Gh.I. Para1

1Институт электронной инженерии и нанотехнологий им. Д. Гицу АН Молдовы ул. Академическая, 3/3, г. Кишинев, МD-2028, Республика Молдова
E-mail: A.Nikolaeva@nano.asm.md

2Международная лаборатория сильных магнитных полей и низких температур ул. Гаявицкая, 95, 53-421, Вроцлав, Польша

3Department of Chemistry, Howard University, 500 College St. N.W., DC 20059 Washington, USA
pos Анотація:

Received August 26, 2016

Abstract

Features of manifestation of Lifshitz electronic topological transitions (ETT) in glass-insulated Bi wires with a qualitive change in the Fermi surface topology have been investigated. The energy spectrum parameters were varied by highly doping Bi wires with Sn at an elastic tension of up to 2% relative extension in weakly doped p-type Bi wires. Pure and doped single- crystal Bi-wires with different diameters and (1011) orientations along the wire axis were prepared by the Ulitovsky liquid phase casting method. ETT-induced anomalies in the form of a triple sign change of thermopower in temperature dependences α(Т) have been first observed in Bi wires highly doped with acceptor (Sn) impurities. The concentration and energy position of the Σ-zone in Bi wires highly doped with the acceptor impurity has been estimated from the Shubnikov de Haas oscillations. It has been shown that Lifshitz ETTs caused by elastic deformation of weakly doped p-type Bi wires are accompanied by anomalies in the deformation dependences of thermopower at low temperatures. The effect has been interpreted in terms of the formation of a selective scattering channel of L- carriers in the T-zone with a high density of states, which is in good agreement with the existing theoretical ETT models.

PACS: 71.30.+h Metal-insulator transitions and other electronic transitions;
PACS: 72.20.My Galvanomagnetic and other magnetotransport effects;
PACS: 72.20.Pa Thermoelectric and thermomagnetic effects.

Key words: electron topological transition, thermopower, Shubnikov de Haas oscillations, doping Bi wires, elastic deformation.

Published online: December 26, 2016

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