Contacting Cu electrodes to Mg2Si0,3Sn0,7: direct vs indirect resistive heating

Abstract

Mg2(Si,Sn)-based thermoelectric materials have been gaining interest in the past years due to their attractive properties. In this work, we present the outcome of using two different approaches to contact nand p- type Mg2Si0.3Sn0.7 legs with Cu electrodes to study the influence of current on the joining procedures. The first approach is a direct current heating procedure where the current runs directly through the sample, while the second approach uses the current as an indirect source of resistive heating. Results show that Cu diffuses into n- and p-type materials, creating relatively thick and complex reaction layers, both under direct and indirect resistive heating, and these layers have, respectively, an average thickness of 200 µm and 100 µm. Electrical contact resistance