Low Temperature Magnetothermoelectric Effect and Magnetoresistance in Te Vapor Annealed Bi₂Te₃

Abstract

The electrical properties of single crystals of p-type Bi2Te3 are shown to be tuned by annealing as-grown crystals in elemental Te vapor at temperatures in the range of 400-420°C. While as-grown nominally stoichiometric Bi2Te3 has p-type conductivity below room temperature, Te vapor annealed Bi2Te3 shows a cross over from p- to n-type behavior. The temperature dependent resistivity of the Te annealed crystals shows a characteristic broad peak near 100 K. Applied magnetic fields give rise to a large low temperature magnetothermoelectric effect in the Te annealed samples and enhance the low temperature peak in the resistivity. Further, Te annealed Bi2Te3 shows a large positive magnetoresistance, ~ 200% at 2 K, and ~ 15% at room temperature. The annealing procedure described can be employed to optimize the properties of Bi2Te3 for study as a topological insulator.

Department(s)

Physics

Keywords and Phrases

Annealed Samples; Annealing Procedures; Applied Magnetic Fields; As-grown; As-grown Crystal; Cross Over; Electrical Property; Low Temperatures; Magnetothermoelectric; P-type; P-type Conductivity; Positive Magnetoresistance; Room Temperature; Te Vapor; Temperature-dependent Resistivity; Electric Resistance; Magnetic Field Effects; Single Crystals; Tellurium Compounds

International Standard Serial Number (ISSN)

0953-8984

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2010 IOP Publishing, All rights reserved.

Publication Date

01 Aug 2010

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