Features of conduction mechanism in n-type Mg2Si1-xSnxsolid solutions


M.I. Fedorov1, D.A. Pshenaj-Severin1,V.K. Zaitsev1, S. Sano2, M.V. Vedernikov1


1A.F.Ioffe Physico-technical Institute,Polytekhnicheskaya ul.26, St.Petersburg,194021, Russia

2Research Center, KomatsuLtd, Hiratsuka, Japan.


N-type Mg2Si1-xSnxsolid solutions are known as efficient thermoelectrics for middle temperature range. High figure of merit ofthis material could be explained by the features of  its band structure. The compounds Mg2Si and Mg2Snhave two close conduction bandsgiving a contribution intotransport properties. In the Mg2Si1-xSnx solidsolutions a convergence of these bands takes place and it is necessary to take intoaccount interband scattering. The analysis of temperaturedependencies of kinetic coefficients was made, where scattering on impurities,acoustical interband and intraband scattering were taken into account. Thecontribution of interbandscattering into Seebeck and Hall coefficients and electrical conductivity isestimated for the solid solutions of various composition and various currentcarrier concentration. A comparison of interband scattering contribution in Mg2Si1-xSnx with that of otherthermoelectrics is made.