Character of Interaction in the SnSb2Te4-SnBi2Te4 System and the Thermoelectric Properties of (SnSb2Te4)1-x(SnBi2Te4)x Solid Solutions

For the first time, the character of the interaction of components along the cut of SnSb2Te4-SnBi2Te4 is studied by various physicochemical methods in a wide temperature range, and the phase diagrams are plotted. The cut is found to be a quasi-binary cross section of the SnTe-Sb2Te3-Bi2Te3 quasi-ternary system. The cut contains the quaternary compound SnSbBiTe4, which melts congruently at 900 K. Single crystals of the quaternary compound SnSbBiTe4 are obtained by the method of chemical transport reactions. X-ray analysis is used to determine the unit-cell parameters a = 4.356 angstrom and c = 41.531 angstrom of single crystals of the quaternary compounds. It is found that the compound crystallizes in the tetradymite lattice of rhombohedral syngony, space group R3m, the charge is z = 3, and the unit-cell volume is V = 682.43 angstrom(3). The thermoelectric parameters of (SnSb2Te4)(1 -)(x)(SnBi2Te4)(x) are measured in the temperature range of 300-600 K. It is found that the thermoelectric figure of merit increased with the SnBi2Te4 content in the solid solutions. The thermoelectric efficiency of (SnSb2Te4)(1 -)(x)(SnBi2Te4)(x) with x = 1.0 has a peak value of Z = 3.1 x 10(-3) K-1 at 300 K.