Thermoelectric properties of Sc- and Y-doped Mg2Si prepared by field-activated and pressure-assisted reactive sintering

Synthesis of Al-doped Mg2Si1−xSnx compound using magnesium alloy for thermoelectric application

“…The thermal diffusivity of Mg 2 Si in Fig. 6(a) is in good agreement with the previous data measured elsewhere and literature [23,25]. The temperature dependence of diffusivity for Mg 2 Sn differs from that for Mg 2 Si.…”

Conducting grain boundaries enhancing thermoelectric performance in doped Mg2Si

“…1(a)-1(d) show the temperature dependence of thermoelectric transport properties, i.e., r(T), a(T), j(T), and the calculated ZT, respectively, of undoped and Pb doped Mg 2 Si along with their comparison with the previously reported studies of doping with Bi, 2 Sb, 3 Te, 4 Al, 5 and Y. 6 It is apparent from this figure that irrespective of nature of the dopant, the overall characteristics of the temperature dependence of their thermoelectric transport parameters appears qualitatively similar. However, substitution of Pb at Si site of Mg 2 Si, resulting in significant enhancement of r(T) ( Fig.…”

“…In general, for a metallic system, r(T) is expected to decrease at high temperatures due to lattice thermal vibrations; however, such a variation is not observed in the doped Mg 2 Si systems. 2,3,5,6 Further, in most of these doped systems, the r(T) increases quite substantially on doping, but the corresponding change in the j(T) is comparatively minimal, thereby suggesting a partial decoupling of the electronic and phonon degrees of freedom. This suggests that the enhancement of ZT in doped Mg 2 Si systems follows not from the material's band structure but has a probable origin at the grain boundaries [21][22][23] or may pertain to the case of metallic nano-inclusions.…”

“…Along these perspectives, doped Mg 2 Si-based systems are promising thermoelectric materials and thus have been extensively studied. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] An added advantage of Mg 2 Si-based thermoelectric materials is the possibility of producing compatible n & p-type thermoelectric elements by suitable doping for thermoelectric devices operating in the intermediate temperature range. An enhanced ZT greater than unity has been accomplished in Mg 2 Si when simultaneously alloyed with Sn with small levels of Sb doping which serves as electron donors.…”

Hot Extruded Polycrystalline Mg2Si with Embedded XS2 Nano-particles (X: Mo, W)

“…4,5 Production techniques for Mg 2 Si are numerous, among them spark plasma sintering (SPS) 11 or fieldactivated and press-assisted sintering (FAPAS). 12,13 In this study, bulk Mg 2 Si-based TE materials are produced through hot extrusion. 14,15 This approach has many advantages over SPS or FAPAS, not only by lowering the sintering temperature, which decreases the chance of contamination, but also by providing a lower cost route to industrial-scale production.…”