Influence of Mg loss on the phase stability in Mg2X (X = Si, Sn) and its correlation with coherency strain

Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg2Si0.3Sn0.7

“…Previous studies have described phase formation from the elements into Mg 2 (Si,Sn) under milling, where, in the presence of both Si and Sn, Mg 2 Sn tends to form first and then Si from brittle elemental debris slowly diffuses into the Mg 2 (Si,Sn) matrix [48]. This process might be influenced by the miscibility gap in the Mg 2 Si-Mg 2 Sn quasibinary system which is controversially discussed [49,50]. However, as discussed in [48], this could be the reason for the observed sharp contrast between regions of different Si content.…”

Applications of thermodynamic calculations to practical TEG design: Mg2(Si0.3Sn0.7)/Cu interconnections

“…Due to their crystallography, they can form a solid solution in the 66.7 at% Mg isopleth of ternary Mg-Si-Sn; however, a wide miscibility gap in the solid phase with controversial solubility limits has been reported in phase equilibria determinations, 17,[21][22][23] and in phase investigations for thermoelectric applications. 24,25 This particular isopleth represents the section Mg 2 Sn-Mg 2 Si with two stable phases: the liquid and the solid Mg 2 Si 1Àx Sn x labelled C1_Mg 2 X, where X ¼ Si, Sn are known to share the same Wyckoff sites. The miscibility gap reported in the solid phase represents the mixture of two conjugated phases or compositions of maximal solubility, and it can be observed in the isothermal section at 600 C in Fig.…”

Phase separation in bismuth doped Mg2Si0.5Ge0.5thermoelectric alloy

“…28 The miscibility gap might even extend into a larger range, 29 explaining the lower k l values observed, beyond the expected just by alloying. 30,31 In a later theoretical analysis, an extension of the miscibility gap toward Mg 2 Ge-richer compositions of the quasi-ternary Mg 2 Si-Mg 2 Sn-Mg 2 Ge phase diagram was also suggested. 32 This opens potential possibilities of k l reduction by morphological and dimensional optimizations of thermodynamically driven phase separation reactions also in the Mg 2 Si x Ge 1Àx system, by controlling the composition and the synthesis procedure parameters.…”