Imperial College London
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Dr Sam Humphry-Baker

Faculty of Engineering, Department of Materials

Lecturer in Ceramics
 
 
 
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Contact

 

s.humphry-baker

 
 
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Location

 

LM.04DRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Humphry-Baker:2014:10.1063/1.4901235,
author = {Humphry-Baker, SA and Schuh, CA},
doi = {10.1063/1.4901235},
journal = {Journal of Applied Physics},
title = {Suppression of grain growth in nanocrystalline Bi2Te3 through oxide particle dispersions},
url = {http://dx.doi.org/10.1063/1.4901235},
volume = {116},
year = {2014}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - <jats:p>The strategy of suppressing grain growth by dispersing nanoscale particles that pin the grain boundaries is demonstrated in a nanocrystalline thermoelectric compound. Yttria nanoparticles that were incorporated by mechanical alloying enabled nanocrystalline (i.e., d &lt; 100 nm) Bi2Te3 to be retained up to a homologous temperature of 0.94 Tm for durations over which the grain size of the unreinforced compound grew to several microns. The nanostructure appeared to saturate at a grain size that depended on volume fraction (f) according to an f−1/3 relationship, in accordance with theoretical models in the limit of high volume fractions of particles. Interestingly, at low temperatures, the particles stimulate enhanced grain growth over the unreinforced compound, due to particle-stimulated nucleation of recrystallization. To help prevent this effect, in-situ composites formed by internal oxidation of yttrium are compared with those made ex-situ by incorporation of yttria nanoparticles, with the result that the in-situ dispersion eliminates recrystallization at low temperatures and therefore improves nanostructure stabilization. These developments offer a pathway to thermally stabilized bulk nanocrystalline thermoelectrics processed via a powder route.</jats:p>
AU  - Humphry-Baker,SA
AU  - Schuh,CA
DO  - 10.1063/1.4901235
PY  - 2014///
SN  - 0021-8979
TI  - Suppression of grain growth in nanocrystalline Bi2Te3 through oxide particle dispersions
T2  - Journal of Applied Physics
UR  - http://dx.doi.org/10.1063/1.4901235
VL  - 116
ER  -
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