Thermoelectrics of n-type with ZT > 1 based on Mg2Si-Mg2Sn solid solutions

The paper presents the results of extensive experimental and theoretical study of the solid solutions in the system Mg₂Si-Mg₂Sn. It is shown that the system is a favorable base for the creation of excellent thermoelectrics with band type of conductivity. The reproducible results are obtained for Seebeck and Hall coefficients, electrical and thermal conductivity in the wide temperature range 77-850 K for the samples of various solid solution composition and various electron concentration (up to 5·10²⁰ cm^-3). At optimum solid solution composition and electron concentration the thermoelectric of ZT_max=1.1 is produced reliably. Average ZT value in the temperature range 350-830 K is about 0.8 for this material. It is shown that the high value of ZT is achieved due to some features of band structure of these materials. It is of great interest that these thermoelectrically remarkable alloys have simple crystallographic structure, made by a traditional technology and are formed from very cheap and ecologically friendly components.