Thermoelectricproperties of Sb-doped Mg₂Si by solid state reaction

L.M.Zhang, C.B. Wang, H.Y. Jiang, Q. Shen

StateKey Lab of Advanced Technology for Materials Synthesis and Processing, WuhanUniversity of Technology, Wuhan 430070, P.R.China

Mg₂Si-based compounds have beenpaid much attention for its cheap, non-poisonous, excellent corrosionresistance and good stability under relative high temperatures. In the presentpaper, Sb-doped Mg₂Si thermoelectric materials were successfullyprepared by solid state reaction at 823K for 8h. Effects of doped Sb on thestructure and thermoelectric properties of the compounds were investigated. Thefigure-of-merit of Mg₂Si increases to 3.3´10^-3K^-1 at about 650Kwhen doped Sb with 0.5% in weight. It is found that, there exists a mutation inthe electric conduction of Sb-doped Mg₂Si near 625K, indicating achange in the energy gap.