Diffusion barriers for CeFe4Sb12/Cu thermoelectric devices

The efficiency of a tantalum nitride interlayer as a diffusion barrier for CeFe 4 Sb 12 thermoelectric material against electrode copper material has been investigated. The thermal stability of CeFe 4 Sb 12 /TaN/Cu stackings has been investigated after annealing at 600°C from a microstructural study. CeFe 4 Sb 12 and Cu appear to chemically react through the formation of CeCu 2 and Cu 2 Sb phases whereas no reaction is observed for CeFe 4 Sb 12 with TaN. This study showed that the TaN interlayer cannot inhibit the diffusion of Sb from the skutterudite substrate to the copper electrode but prevents the diffusion of Ce and consequently the formation of the CeCu 2 phase.