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Title: Synthesis and characterization of Bi-doped Mg{sub 2}Si thermoelectric materials

Abstract

The Mg{sub 2}Si-based alloys are promising candidates for thermoelectric energy conversion for the middle high range of temperature. They are very attractive as they could replace lead-based compounds due to their low cost and non toxicity. They could also result in thermoelectric generator weight reduction (a key feature for the automotive application field). The high value of thermal conductivity of the silicide-based materials could be reduced by increasing the phonon scattering in the presence of nanosized crystalline grains without heavily interfering with the electrical conductivity of the thermoelectric material. Nanostructured materials were obtained under inert atmosphere through ball milling, thermal treatment and spark plasma sintering processes. In particular, the role of several bismuth doping amounts in Mg{sub 2}Si were investigated (Mg{sub 2}Si:Bi=1:x for x=0.01, 0.02 and 0.04 M ratio). The morphology, the composition and the structure of the samples were characterized by FE-SEM, EDS and XRD analyses after each process step. Moreover, the Seebeck coefficient analyses at high temperature and the electrical and thermal conductivity of the samples are presented in this work. The nanostructuring processes were affect by the MgO amount increase which influenced the thermoelectric properties of the samples mainly by reducing the electrical conductivity. With the aimmore » of further increasing the scattering phenomena by interface or boundary effect, carbon nanostructures named Single Wall Carbon Nanohorns were added to the Mg{sub 2}Si in order to produce a nanocomposite material. The influence of the nanostructured filler on the thermoelectric material properties is also discussed. - Graphical abstract: Figure of merit (ZT) of Bi-doped samples and undoped Mg{sub 2}Si. A maximum ZT value of 0.39 at 600 Degree-Sign C was obtained for the nanocomposite material obtained adding Single Wall Carbon Nanohorns to the Bi 0.02 at% doped silicide. Highlights: Black-Right-Pointing-Pointer Role of Bi doping amounts in Mg{sub 2}Si and thermoelectric characterization up to 600 Degree-Sign C Black-Right-Pointing-Pointer Nanocomposite materials synthesized by ball milling and Spark Plasma Sintering Black-Right-Pointing-Pointer Effect on scattering phenomena of Single Wall Carbon Nanohorns added to Mg{sub 2}Si Black-Right-Pointing-Pointer Importance of oxidation phenomena in nanostructured materials.« less

Authors:
; ; ; ; ;  [1]
  1. CNR - IENI, Corso Stati Uniti 4, 35127 Padova (Italy)
Publication Date:
OSTI Identifier:
22149815
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 193; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ALLOYS; CARBON; CHEMICAL PREPARATION; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; HEAT TREATMENTS; MAGNESIUM SILICIDES; NANOSTRUCTURES; SCANNING ELECTRON MICROSCOPY; THERMAL CONDUCTIVITY; THERMOELECTRIC GENERATORS; THERMOELECTRIC MATERIALS; THERMOELECTRIC PROPERTIES; X-RAY DIFFRACTION; NESDPS Office of Nuclear Energy Space and Defense Power Systems

Citation Formats

Fiameni, S., E-mail: s.fiameni@ieni.cnr.it, Battiston, S., Boldrini, S., Famengo, A., Agresti, F., Barison, S., and Fabrizio, M. Synthesis and characterization of Bi-doped Mg{sub 2}Si thermoelectric materials. United States: N. p., 2012. Web. doi:10.1016/J.JSSC.2012.05.004.
Fiameni, S., E-mail: s.fiameni@ieni.cnr.it, Battiston, S., Boldrini, S., Famengo, A., Agresti, F., Barison, S., & Fabrizio, M. Synthesis and characterization of Bi-doped Mg{sub 2}Si thermoelectric materials. United States. https://doi.org/10.1016/J.JSSC.2012.05.004
Fiameni, S., E-mail: s.fiameni@ieni.cnr.it, Battiston, S., Boldrini, S., Famengo, A., Agresti, F., Barison, S., and Fabrizio, M. 2012. "Synthesis and characterization of Bi-doped Mg{sub 2}Si thermoelectric materials". United States. https://doi.org/10.1016/J.JSSC.2012.05.004.
@article{osti_22149815,
title = {Synthesis and characterization of Bi-doped Mg{sub 2}Si thermoelectric materials},
author = {Fiameni, S., E-mail: s.fiameni@ieni.cnr.it and Battiston, S. and Boldrini, S. and Famengo, A. and Agresti, F. and Barison, S. and Fabrizio, M.},
abstractNote = {The Mg{sub 2}Si-based alloys are promising candidates for thermoelectric energy conversion for the middle high range of temperature. They are very attractive as they could replace lead-based compounds due to their low cost and non toxicity. They could also result in thermoelectric generator weight reduction (a key feature for the automotive application field). The high value of thermal conductivity of the silicide-based materials could be reduced by increasing the phonon scattering in the presence of nanosized crystalline grains without heavily interfering with the electrical conductivity of the thermoelectric material. Nanostructured materials were obtained under inert atmosphere through ball milling, thermal treatment and spark plasma sintering processes. In particular, the role of several bismuth doping amounts in Mg{sub 2}Si were investigated (Mg{sub 2}Si:Bi=1:x for x=0.01, 0.02 and 0.04 M ratio). The morphology, the composition and the structure of the samples were characterized by FE-SEM, EDS and XRD analyses after each process step. Moreover, the Seebeck coefficient analyses at high temperature and the electrical and thermal conductivity of the samples are presented in this work. The nanostructuring processes were affect by the MgO amount increase which influenced the thermoelectric properties of the samples mainly by reducing the electrical conductivity. With the aim of further increasing the scattering phenomena by interface or boundary effect, carbon nanostructures named Single Wall Carbon Nanohorns were added to the Mg{sub 2}Si in order to produce a nanocomposite material. The influence of the nanostructured filler on the thermoelectric material properties is also discussed. - Graphical abstract: Figure of merit (ZT) of Bi-doped samples and undoped Mg{sub 2}Si. A maximum ZT value of 0.39 at 600 Degree-Sign C was obtained for the nanocomposite material obtained adding Single Wall Carbon Nanohorns to the Bi 0.02 at% doped silicide. Highlights: Black-Right-Pointing-Pointer Role of Bi doping amounts in Mg{sub 2}Si and thermoelectric characterization up to 600 Degree-Sign C Black-Right-Pointing-Pointer Nanocomposite materials synthesized by ball milling and Spark Plasma Sintering Black-Right-Pointing-Pointer Effect on scattering phenomena of Single Wall Carbon Nanohorns added to Mg{sub 2}Si Black-Right-Pointing-Pointer Importance of oxidation phenomena in nanostructured materials.},
doi = {10.1016/J.JSSC.2012.05.004},
url = {https://www.osti.gov/biblio/22149815}, journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = ,
volume = 193,
place = {United States},
year = {Sat Sep 15 00:00:00 EDT 2012},
month = {Sat Sep 15 00:00:00 EDT 2012}
}