Thermoelectric performance of skutterudite NixCo4−xSb12 rapidly synthesized by microwave heating

In the present work, a series of single phase Ni-doped skutterudite compounds Ni x Co 4−x Sb 12 (x = 0.1, 0.2, 0.3, 0.4, 0.5) were successful synthesized by 5 min microwave heating for the first time. The resulting ingots was pulverized and sintered by spark plasma sintering to fabricate bulk samples, and their microstructure and thermoelectric properties have been investigated systematically. The results show that the matrix grain characteristics are influenced by Ni concentration and microwave irradiation. The Ni 0.3 Co 3.7 Sb 12 bulk has the smallest and uniform grain size of about 1–2 µm. The maximum power factors of Ni x Co 4−x Sb 12 are 2273, 2479, 2711, 2613 and 2526 µWm −1 K −2 respectively. A highest ZT of 0.52 for Ni 0.3 Co 3.7 Sb 12 is achieved at 773 K along with a total thermal conductivity of 3.8 Wm −1 K −1 .