Structural, thermoelectric and stability studies of Fe-doped copper sulfide
Andrzej Mikuła, Paweł Nieroda, Krzysztof Mars, Juliusz Dąbrowa, Andrzej Koleżyński
Abstract
A multi-phase composite based on the copper sulfide and bornite phases was obtained. The sintering process (inductive hot pressing method) and multiple thermoelectric measurements lead, however, to complete reconstruction of the structure. Structural, thermoelectric and stability studies indicate that the final material initially consisting of 90% Cu2S and 10% Cu5FeS4 is characterized by a thermoelectric figure of merit (ZT) of about 1.0 (900 [K]) with significantly improved stability in comparison to bulk Cu2S-based materials. The presence of iron-rich phases stabilizes the high-symmetrical forms of Cu2S without precipitation of free Cu related to excessive mobility of these ions.