Thermoelectric properties of p‐type Mg₂Si_0.6Ge_0.4 fabricated by bulk mechanical alloying and hot pressing

Abstract

Bulk mechanical alloying (BMA) followed by hot pressing (HP) was used to prepare Mg2Si0.6Ge0.4 thermoelectric material with high densification. Starting from the elemental power mixture, the Mg2Si0.6Ge0.4 solid solution was solid‐state synthesized via BMA. In fact, the peaks for the cubic‐structured Mg2Si0.6Ge0.4 solid solution phase were detected after 300 cycles in BMA. The single phase of Mg2Si0.6Ge0.4 was synthesized at 600 cycles in BMA. Mg2Si0.6Ge0.4 showed p‐type semiconduction without doping. Effects of hot pressing conditions on thermoelectric properties were investigated. With increasing hot pressing temperature from 673 to 773 K and pressure from 500 MPa to 1 GPa, the electrical conductivity increased and the Seebeck coefficient decreased. The maximum figure of merit was obtained with the processing parameter of 600 cycles BMA and hot pressing at 773 K, 1 GPa for 1 h. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Growth and Characterization of Thermoelectric Mg2Si Thin Films

“…Mg 2 Si has drawn much of attention as a candidate thermoelectric compound [2]. Bulk Mg 2 Si is typically prepared by Bridgman method [3] or spark plasma sintering (SPS) technique [4], while, recently mechanical alloying followed by hot pressing has been reported [5]. The n-type material, obtained by alloying with Sn has a high ZT, up to 1.1, at about 900K [2(a)].…”