Preparation and transport properties of CeSi2/HMS thermoelectric composites

The composites of higher manganese silicide (HMS) and CeSi2 were fabricated in the formulation of (CeSi2)x(MnSi1.75)1−x (x = 0, 0.01, 0.03, 0.045, 0.06, 0.08, and 0.1) by rapid solidification followed by hot-pressing. The phase structures and morphologies of the hot-pressed composites were investigated, and the Seebeck coefficient and the electrical conductivity were measured from 300 K to 1050 K. The dual effect of lattice scattering and the intrinsic excitation of carriers were discussed on the temperature dependences of the Seebeck coefficient and the electrical conductivity. It was found that the CeSi2 particles distribute primarily on the HMS grain boundaries. The addition of CeSi2 reduced the Seebeck coefficient and increased the electrical conductivity of HMS. The power factors were also decreased by the addition of CeSi2.