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Title: Lattice dynamics and thermoelectric properties of nanocrystalline silicon-germanium alloys

Abstract

The lattice dynamics and thermoelectric properties of sintered phosphorus-doped nanostructured silicon- germanium alloys obtained by gas-phase synthesis were studied. Measurements of the density of phonon states by inelastic neutron scattering were combined with measurements of the elastic constants and the low- temperature heat capacity. A strong influence of nanostructuring and alloying on the lattice dynamics was observed. The thermoelectric transport properties of samples with different doping as well as samples sintered at different temperature were characterized between room temperature and 1000C. A peak figure of merit zT = 0:88 at 900C is observed and comparatively insensitive to the aforementioned param- eter variations.

Authors:
 [1];  [2];  [2];  [3];  [4];  [2];  [1];  [2];  [5]
  1. Julich Research Centre (Germany). Julich Centre for Neutron Science (JCNS)
  2. University of Duisburg-Essen (Germany)
  3. Forschungszentrum Julich (Germany)
  4. Inst. Laue-Langevin (ILL), Grenoble (France)
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1240536
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physica Status Solidi. A, Applications and Materials Science
Additional Journal Information:
Journal Volume: 213; Journal Issue: 3; Journal ID: ISSN 1862-6300
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SiGe alloy; thermoelectric; lattice dynamics; transport properties

Citation Formats

Claudio, Tania, Stein, Niklas, Peterman, Nils, Stroppa, Daniel, Koza, Michael M., Wiggers, Hartmut, Klobes, B., Schierning, Gabi, and Hermann, Raphael P.. Lattice dynamics and thermoelectric properties of nanocrystalline silicon-germanium alloys. United States: N. p., 2015. Web. doi:10.1002/pssa.201532500.
Claudio, Tania, Stein, Niklas, Peterman, Nils, Stroppa, Daniel, Koza, Michael M., Wiggers, Hartmut, Klobes, B., Schierning, Gabi, & Hermann, Raphael P.. Lattice dynamics and thermoelectric properties of nanocrystalline silicon-germanium alloys. United States. doi:10.1002/pssa.201532500.
Claudio, Tania, Stein, Niklas, Peterman, Nils, Stroppa, Daniel, Koza, Michael M., Wiggers, Hartmut, Klobes, B., Schierning, Gabi, and Hermann, Raphael P.. Mon . "Lattice dynamics and thermoelectric properties of nanocrystalline silicon-germanium alloys". United States. doi:10.1002/pssa.201532500. https://www.osti.gov/servlets/purl/1240536.
@article{osti_1240536,
title = {Lattice dynamics and thermoelectric properties of nanocrystalline silicon-germanium alloys},
author = {Claudio, Tania and Stein, Niklas and Peterman, Nils and Stroppa, Daniel and Koza, Michael M. and Wiggers, Hartmut and Klobes, B. and Schierning, Gabi and Hermann, Raphael P.},
abstractNote = {The lattice dynamics and thermoelectric properties of sintered phosphorus-doped nanostructured silicon- germanium alloys obtained by gas-phase synthesis were studied. Measurements of the density of phonon states by inelastic neutron scattering were combined with measurements of the elastic constants and the low- temperature heat capacity. A strong influence of nanostructuring and alloying on the lattice dynamics was observed. The thermoelectric transport properties of samples with different doping as well as samples sintered at different temperature were characterized between room temperature and 1000C. A peak figure of merit zT = 0:88 at 900C is observed and comparatively insensitive to the aforementioned param- eter variations.},
doi = {10.1002/pssa.201532500},
journal = {Physica Status Solidi. A, Applications and Materials Science},
number = 3,
volume = 213,
place = {United States},
year = {Mon Oct 26 00:00:00 EDT 2015},
month = {Mon Oct 26 00:00:00 EDT 2015}
}

Journal Article:
Free Publicly Available Full Text
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Citation Metrics:
Cited by: 1work
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  • The lattice dynamics and thermoelectric properties of sintered phosphorus-doped nanostructured silicon–germanium alloys obtained by gas-phase synthesis were studied. Measurements of the density of phonon states by inelastic neutron scattering were combined with measurements of the elastic constants and the low-temperature heat capacity. A strong influence of nanostructuring and alloying on the lattice dynamics was observed. The thermoelectric transport properties of samples with different doping as well as samples sintered at different temperature were characterized between room temperature and 1000°C. A peak figure of merit zT=0.88 at 900°C is observed and is comparatively insensitive to the aforementioned parameter variations.
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  • We report the synthesis and chemical, structural, and transport properties characterization of Ba8Ga16SixGe30-x type I clathrates with similar Ga-to-group IV element ratios but with increasing Si subsitution (4 < x < 14). Substitution of 20 at. % Si within the Ga-Ge lattice framework of the type I clathrate Ba8Ga16Ge30 results in thermoelectric enhancement. The unique dependences of n, , |S|, and m* with Si substitution, and the lack of variation in the Ga-to-group IV element ratios may imply a modified band structure with x. These results indicate an additional method in tuning the electronic properties of Ba8Ga16Ge30 for thermoelectric applications.