Title :
Thermoelectric Properties of Mg2Si Doped with Bi and Al with Conductive Glass Inclusion
Author :
Satyala, Nikhil T. ; Krasinski, Jerzy S. ; Vashaee, Daryoosh
Author_Institution :
Helmerich Adv. Technol. Res. Center, Oklahoma State Univ., Tulsa, OK, USA
Abstract :
The thermoelectric (TE) properties of magnesium silicide (Mg2Si) fabricated through mechanical alloying and hot-pressing have been characterized by measurements of electrical resistivity (ρ), Seebeck coefficient (S) and thermal conductivity (κ) between 300 K and 970 K. TE samples of 2-at% Bi doped and 2-at% Al doped specimens were sintered at 1173 K and 1123 K, respectively. Structural analysis of the sintered samples was performed by scanning electron microscopy. The effect of inclusion of a minuscule quantity (0.25-vol%) of Mg-Si-B-R based conductive glass-frit in order to reduce the brittleness of samples has been investigated on the Al-doped Mg2Si samples. Power factors (S2σT) of greater than 2 W/mK were obtained from samples doped with Al. The samples mixed with conductive glass frit have also exhibited higher stability at temperatures greater than 900 K when compared to samples doped with Bi. The Mg2Si:Bi and Mg2Si:Al samples showed a maximum figure-of- merit (ZT) of 0.53 and 0.66 at 970 K, respectively.
Keywords :
Seebeck effect; aluminium; bismuth; brittleness; crystal structure; electrical resistivity; glass; hot pressing; magnesium compounds; mechanical alloying; mixing; scanning electron microscopy; semiconductor materials; silicon compounds; sintering; thermal conductivity; thermal stability; thermoelectric power; Mg2Si:Al-SiO2; Mg2Si:Bi-SiO2; Seebeck coefficient; brittleness; conductive glass inclusion; electrical resistivity; figure-of-merit; hot pressing; magnesium silicide; mechanical alloying; mixing; power factor; scanning electron microscopy; semiconductor materials; sintering; structural analysis; temperature 1123 K; temperature 1173 K; temperature 300 K to 970 K; thermal conductivity; thermal stability; thermoelectric properties; Bismuth; Conductivity; Reactive power; Scanning electron microscopy; Temperature; Temperature measurement; Thermal conductivity;
Conference_Titel :
Green Technologies Conference, 2012 IEEE
Conference_Location :
Tulsa, OK
Print_ISBN :
978-1-4673-0968-4
Electronic_ISBN :
2166-546X
DOI :
10.1109/GREEN.2012.6200960
