Development of improved {ital p}-type Si-20 at. % Ge by addition of fullerite
- Ames Laboratory, Iowa State University, Ames, Iowa (United States)
In a series of experiments designed to evaluate the possibility of lowering the lattice thermal conductivity of silicon-germanium alloys through the formation of an inert, intragranular nanophase, a number of {ital p}-type Si-20 at. % Ge alloys, with a nominal doping level of 0.5 at. % boron, were prepared with varying amounts of fullerite, a mixture of 90% C{sub 60}+10% C{sub 70} with a particle size of 0.7 nm. The alloys were synthesized by mechanical alloying (MA) and the fullerite was added at various stages of the preparation sequence. Compacts consolidated by hot pressing at temperatures of 1200 {degree}C to 1265 {degree}C were found to be fully dense and homogeneous. Each compact was characterized by Hall effect at room temperature and also by electrical resistivity, Seebeck coefficient, and thermal diffusivity measurements to 1000 {degree}C. A reduction in thermal conductivity of up to 22% compared to standard {ital p}-type alloys was observed in samples containing 0.8 weight percent additions. In this study, a maximum integrated average figure of merit, {ital Z}, between 300 and 1000 {degree}C of 0.65{times}10{sup {minus}3} {degree}C{sup {minus}1} was obtained, corresponding to 0.4 weight percent addition of fullerite. Observation of selected samples by transmission electron microscopy revealed that the fullerite reacted with silicon to form nanophase SiC inclusions. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- Research Organization:
- Ames National Laboratory
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 83891
- Report Number(s):
- CONF-940830--
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 316; ISSN 0094-243X; ISSN APCPCS
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of improved p-type Si-20 at. % Ge by addition of fullerite
Thermoelectric properties of mechanically alloyed p -type Si sub 80 Ge sub 20 alloys
Electrical properties of Ga and ZnS doped ZnO prepared by mechanical alloying
Conference
·
Fri Dec 30 23:00:00 EST 1994
·
OSTI ID:46458
Thermoelectric properties of mechanically alloyed p -type Si sub 80 Ge sub 20 alloys
Conference
·
Mon Dec 31 23:00:00 EST 1990
· AIP Conference Proceedings (American Institute of Physics); (United States)
·
OSTI ID:5685797
Electrical properties of Ga and ZnS doped ZnO prepared by mechanical alloying
Journal Article
·
Mon Jun 01 00:00:00 EDT 1998
· Journal of Applied Physics
·
OSTI ID:604411