YCuTe 2 : a member of a new class of thermoelectric materials with CuTe 4 -based layered structure

YCuTe 2 : a member of a new class of thermoelectric materials with CuTe 4 -based layered structure

TitleYCuTe 2 : a member of a new class of thermoelectric materials with CuTe 4 -based layered structure
Publication TypeJournal Article
Year of Publication2016
AuthorsUmut Aydemir, Jan-Hendrik Pöhls, Hong Zhu, Geoffroy Hautier, Saurabh Bajaj, Zachary M Gibbs, Wei Chen, Guodong Li, Saneyuki Ohno, Danny Broberg, Stephen Dongmin Kang, Mark Asta, Gerbrand Ceder, Mary Anne White, Kristin A Persson, Anubhav Jain, G. Jeffrey Snyder
JournalJournal of Materials Chemistry A
Volume4
Issue7
Pagination2461 - 2472
Date Published01/2016
ISSN2050-7488
Abstract

Intrinsically doped samples of YCuTe2 were prepared by solid state reaction of the elements. Based on the differential scanning calorimetry and the high temperature X-ray diffraction analyses, YCuTe2 exhibits a first order phase transition at 440 K from a low-temperature-phase crystallizing in the space group P3m1 to a high-temperature-phase in P3. Above the phase transition temperature, partially ordered Cu atoms  become completely disordered in the crystal structure. Small increases to the Cu content are observed to favour the formation of the high temperature phase. We find no indication of superionic Cu ions as for binary copper chalcogenides (e.g., Cu2Se or Cu2Te). All investigated samples exhibit very low thermal conductivities (as low as 0.5 W m1 K1 at 800 K) due to highly disordered Cu atoms. Electronic structure calculations are employed to better understand the high thermoelectric efficiency for YCuTe2. The maximum thermoelectric figure of merit, zT, is measured to be 0.75 at 780 K for Y0.96Cu1.08Te2, which is promising for mid-temperature thermoelectric applications.

DOI10.1039/C5TA10330D
Short TitleJ. Mater. Chem. A
Refereed DesignationRefereed