ICT2014 Abstracts

Higher manganese silicide (HMS) is an environment-friendly p-type thermoelectric material with attractive performance and highly stability in intermediate temperature range (500~800K). Due to the high melting point of HMS, the preparation methods reported previously always contain energy-intensive processes with long preparation period and high cost. In this study, thermal explosion (TE) was unprecedentedly adopted for facile preparation of high performance HMS via a low cost route. During a typical TE process, nanostructured polycrystalline single-phase HMS with excellent thermoelectric performance could be easily obtained in an ultra-short period of time (less than 10min). Then the dense bulks were prepared by a rapid plasma actived sintering (PAS) technique. As compared with those prepared by solid-state reaction or induction melt process, HMS obtained by TE process exhibits smaller grain sizes and cleaner grain boundaries, which are considered responsible for the lower lattice thermal conductivity and higher carrier mobility observed. Results show that the Ge doping sample Mn(Ge_0.01Si_0.99)_1.75 prepared via TE-PAS technique exhibits a maximum ZT of 0.6 at 800K, which demonstrated the TE-PAS technique a versatile route for rapid preparation of HMS and other thermoelectric materials.