Mechanism of conductivity and thermoelectric efficiency of rare earth chalcogenides

To evaluate the possible use of chalkogenides of rare earth elements in thermoelectric energetics, the thermoelectric efficiency of chalkogenides of rare earth elements of Lnsub(3-x X4 (where 0<=X<=0 33; Ln - La, Ce, Pr, Nd; X - S, Se - Te) has been studied within the temperature range from 1300 to 1800 K. It has been established that Z high thermoelectric efficiency is realized when there are a standard zone and usual scattering on lattice vibrations at high temperatures. La3Te4, among the compounds under study, possesses the highest efficiency (Z=0.9x10-3 deg-1 or T=1550 K). Jump conductivity, at which Z increases at high temperatures, is not realized for these materials