Silicide based material and unicouple test under large temperature

Mg2Si and related alloys have been considered appealing candidates as thermoelectric materials in the middle-high temperature range since their low toxicity, their low densities and the abundance of the constituent elements. In this work Mg2Si based (n-type) and higher manganese silicide (p-type) samples were tested under large temperature difference in a specifically designed test station. I-V curves and ZT direct measurement [1] were obtained in order to estimate their power density and efficiency. Results were compared with ZT values obtained by the independent measurements of ?, ? and ?. The role of the contact pressure on the thermal contact resistance was also evaluated. Furthermore, thermoelectric and thermal expansion compatibility between n- and p-type legs were investigated by means of finite element analysis and dilatometry: a unicouple device prototype based on these n- and p-type materials was produced and tested under realistic operating conditions.