title: Nanostructured Bi2Te3 Prepared by a Straightforward Arc-Melting Method.
abstract: Thermoelectric materials constitute an alternative source of sustainable energy, harvested from waste heat. Bi2Te3 is the most utilized thermoelectric alloy. We show that it can be readily prepared in nanostructured form by arc-melting synthesis, yielding mechanically robust pellets of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanning electron microscopy (SEM), and electronic and thermal transport measurements. A microscopic analysis from NPD data demonstrates a near-perfect stoichiometry of Bi2Te3 and a fair amount of anharmonicity of the chemical bonds. The as-grown material presents a metallic behavior, showing a record-low resistivity at 320 K of 2 μΩ m, which is advantageous for its performance as a thermoelectric material. SEM analysis shows a stacking of nanosized sheets, each of them presumably single-crystalline, with large surfaces perpendicular to the c crystallographic axis. This nanostructuration notably affects the thermoelectric properties, involving many surface boundaries that are responsible for large phonon scattering factors, yielding a thermal conductivity as low as 1.2 W m(-1) K(-1) around room temperature.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.|National School of Engineers, Sfax University, Sfax, B. P. W 3038, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Gharsallah
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Serrano-Sánchez
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Bermúdez
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.
authors.forename: N M
authors.initials: NM
authors.lastname: Nemes
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Martínez
authors.affiliation: National School of Engineers, Sfax University, Sfax, B. P. W 3038, Tunisia.
authors.forename: F
authors.initials: F
authors.lastname: Elhalouani
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain. ja.alonso@icmm.csic.es.
authors.forename: J A
authors.identifier: http://orcid.org/0000-0001-5329-1225
authors.initials: JA
authors.lastname: Alonso
keywords: Lattice thermal conductivity; Nanostructuration; Neutron powder diffraction; Thermoelectrics; Thermopower; ZT figure of merit