Contacting Cu Electrodes to Mg2Si0.3Sn0.7: Direct vs. Indirect Resistive Heating

On the relevance of point defects for the selection of contacting electrodes: Ag as an example for Mg2(Si,Sn)-based thermoelectric generators

“…One of the also frequently studied TE materials are Mg2Si1-xSnx solid solutions as they consist of abundant elements, are environmentally friendly, and have improved thermoelectric properties compared to their binaries [17][18][19][20][21]. Contacting of Mg2Si1-xSnx materials was tested using Ag [22] Ni [22][23][24] and Cu [7,25,26] electrodes, and electrical contact resistances and microstructure of the reaction layers were reported.…”

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

“…Contacting an electrode with a Zn layer implies that some Zn could diffuse into the TE material. This can potentially have detrimental effects on the TE properties (and potentially also on the thermal stability of the material) as was already observed with other electrodes such as Ag and Cu [29,32,39]. In order to check for those effects, Seebeck coefficient measurements were performed and reported in Figure 4.…”

“…The solid solution Mg 2 (Si,Sn) pellets were prepared similarly to what was reported in previously published papers [27,[30][31][32], with the following nominal stoichiometry: Mg 2.06 Si 0.3 Sn 0.665 Bi 0.035 for n-type and Mg 1.98 Li 0.03 Si 0.3 Sn 0.7 for p-type. The n-type composition contains Mg with an excess of 3% in order to compensate for the Mg evaporation occurring during the sintering, due to its longer duration compared to p-type samples.…”

Effect of joining temperature on the interconnection zone and electrical resistance of Ag/n-Mg2Si and Ag/n-Mg2Sn contacts

“…30 The current densities are calculated by eqn (5) by considering the intrinsic TE properties after joining and the PSM current densities are given by I PSM /A. 28 As the r c values are different for both sides, they are separately indicated in the table as left and right side of the figure. The reliability of the results of this table can be validated by comparing the values from eqn (3) and ( 4).…”

“…Besides, the Mg 2 (Si,Sn) system has proven to demix not only after synthesis, 13,26 but also after joining, notably after Cu and Ag joining. 25,[27][28][29] Therefore, conducting contact development studies on the binaries Mg 2 Si and Mg 2 Sn serves the purpose of less complex conditions. In this way, any influence of demixing of the matrix can be eliminated.…”