Year: 2008
Type: article
Abstract: First-principles calculation revealed that Na atoms were expected to be primarily located Mg sites in Mg2Si. Densities of electronic states of the Na-doped Mg2Si showed p-type. To obtain a good p-type thermoelectric material, Na-doped Mg2Si (Mg66.7-xSi33.3Nax) were fabricated by solid-liquid reaction using spark plasma sintering. The X-ray diffraction experiments showed that the prepared samples were composed of a single Mg2Si phase. Electrical resistivity, ρ, and Seebeck coefficient, α, were measured in the temperature range from room temperature to around 600 K for samples with various Na contents. The α of samples in the Na composition range of x≥0.5 were positive values (p-type). The results of first-principles calculation and experiment showed that Na was employed as acceptor in Mg2Si system. The maximum power factor of 0.44×10-3 W•m-1•K-2 was obtained at 313 K for the Mg65.7Si33.3Na1.0 sample.
Authors: Yosuke Niwa, Yoshikazu Todaka, Minoru Umemoto, Keita Yamana, Kyoichi Kinoshita, Motoharu Tanizawa
Institutions: Toyohashi University of Technology, Toyota Industries (Japan)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2511340288