Abstract
(Bi1-xSbx)2Te3 is important for thermoelectric applications, and Sn is the base element for almost all the electronic solders. The interfacial reactions between in the Sn/Bi2Te3, Sn/(Bi0.25Sb0.75)2Te3 and Sn/Sb2Te3 at 250°C are examined. It has been found that the interfacial reaction rates are enormously fast in all these three kinds of couples, and the growth rates of the layers are 39m/min, 27m/min and 19m/min, respectively. The reaction products are primarily the SnTe phase. An interesting Sn3Sb2/SnTe alternating layer microstructure is observed in the Sn/(Bi0.25Sb0.75)2Te3 and Sn/Sb2Te3 couples reacted for longer than 15 minutes. Bi precipitates were found as well in the reaction zone in the Sn/(Bi0.25Sb0.75)2Te3 couples in the later stage of reactions. The alternating layer and Bi precipitates are resulted from supersaturation of Sb and Bi in the reaction layer which is caused by the fast incoming flux of Sn