Synthesis and thermoelectric properties of Mg2Si1-xSnx solid solutions by microwave irradiation

摘要

In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil?xSnx(x=0.2,0.4,0.6,0.8) solid solutions,microwave irradiation techniques were used in preparing them as thermoelectric materials.Structure and phase composition of the obtained materials were investigated by X-ray diffraction(XRD).The electrical conductivity,Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K.It is found that Mg2Sil?xSnx solid solutions are well formed with excessive content of 5%(molar fraction) Mg from the stoichiometric Mg2Sil-xSnx under microwave irradiation.A maximum dimensionless figure of merit,ZT,of about 0.26 is obtained for Mg2Sil?xSnx solid solutions at about 500 K for x=0.6.