Year: 2012
Type: article
Abstract: Rare-earth elements (Re) Sc and Y doped Mg 2 Si thermoelectric materials were made via a field-activated and pressure-assisted synthesis (FAPAS) method at 1023–1073 K, 50 MPa for 15 min. The samples created using this method have uniform and compact structures. The average grain size was about 1.5–2 μm, the micro-content of Re did not change the matrix morphology. The sample with 2500 ppm Sc obtained the best See-beck coefficient absolute value, about 1.93 times of that belonging to non-doped Mg 2 Si at about 408 K. The electric conductivity of the sample doped with 2000 ppm Y becomes 1.69 times of that of pure Mg 2 Si at 468 K, while the former had a better comprehensive electrical performance. Their thermal conductivity was reduced to 70% and 84% of that of non-doped Mg 2 Si. Thus, the figure of merit and ZT of these two samples were enhanced visibly, which were 3.3 and 2.4 times of the non-doped samples at 408 K and 468 K, respectively. The maximal ZT belonging to samples doped with 2500 ppm Sc went up to 0.42 at about 498 K, higher than 0.40 of sample doped with 2000 ppm Y at 528 K and 0.25 of non-doped Mg 2 Si at 678 K, and the samples doped with Sc seemed to get the best thermoelectric performances at lower temperature.
Source: Journal of Semiconductors
Authors: Liqi Wang, Qingsen Meng, Wenhao Fan
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
Award: G936320291
OpenAlex ID: W2256807311