skip to main content

DOE PAGESDOE PAGES

Title: Misfit layer compounds and ferecrystals: Model systems for thermoelectric nanocomposites

A basic summary of thermoelectric principles is presented in a historical context, following the evolution of the field from initial discovery to modern day high-zT materials. A specific focus is placed on nanocomposite materials as a means to solve the challenges presented by the contradictory material requirements necessary for efficient thermal energy harvest. Misfit layer compounds are highlighted as an example of a highly ordered anisotropic nanocomposite system. Their layered structure provides the opportunity to use multiple constituents for improved thermoelectric performance, through both enhanced phonon scattering at interfaces and through electronic interactions between the constituents. Recently, a class of metastable, turbostratically-disordered misfit layer compounds has been synthesized using a kinetically controlled approach with low reaction temperatures. The kinetically stabilized structures can be prepared with a variety of constituent ratios and layering schemes, providing an avenue to systematically understand structure-function relationships not possible in the thermodynamic compounds. We summarize the work that has been done to date on these materials. The observed turbostratic disorder has been shown to result in extremely low cross plane thermal conductivity and in plane thermal conductivities that are also very small, suggesting the structural motif could be attractive as thermoelectric materials if the power factormore » could be improved. The first 10 compounds in the [(PbSe)1+δ]m(TiSe₂)n family (m, n ≤ 3) are reported as a case study. As n increases, the magnitude of the Seebeck coefficient is significantly increased without a simultaneous decrease in the in-plane electrical conductivity, resulting in an improved thermoelectric power factor.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Univ. of Oregon, Eugene, OR (United States)
Publication Date:
OSTI Identifier:
1184842
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Materials
Additional Journal Information:
Journal Volume: 8; Journal Issue: 4; Journal ID: ISSN 1996-1944
Publisher:
MDPI
Research Org:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE thermoelectric materials; misfit layer compound; ferecrystal; electrical transport