Phase diagram of In–Co–Sb system and thermoelectric properties of In-containing skutterudites

• DOI: 10.1039/c3ee43240h
• Publication Date: 2013-12-06T15:37:38Z
• Authors: Yinglu Tang; Yuting Qiu; Lili Xi; Xun Shi; Wenqing Zhang; Lidong Chen; Ssu-Ming Tseng; Sinn-wen Chen; G. Jeffrey Snyder
• Keywords: Skutterudite; Isothermal process

In-containing skutterudites have long attracted much attention and debate partly due to the solubility limit issue of indium in CoSb3. The isothermal section equilibrium phase diagram for In–Co–Sb system at 873 K is proposed using knowledge related binary diagrams experimental data, which explains debated that depends on Sb content. In this paper, a series skutterudite samples (InxCo4Sb12−x/3 with x varying from 0.075 0.6 In0.3Co4−ySb11.9+y y changing −0.20 0.20) are synthesized characterized. X-ray analysis scanning electron microscopy images indicate that, up = 0.27, single-phase obtained lattice constant increasing fraction x. A fixed-composition In0.27±0.01Co4Sb11.9 was determined Co-rich side In–CoSb3 coexistence liquid InSb CoSb2. Indium, like Ga, expected, DFT calculations, form compound defects skutterudites. However, relatively higher carrier concentrations compared Ga-containing existence not fully charge-compensated defects, can also be explained by calculations. net n-type concentration naturally forms complex close optimum thermoelectric performance, enabling maximum zT 1.2 fixed composition In0.27Co4Sb11.9 750 K.