OBTAINING AND INVESTIGATIONS OF COMPOSITION AND THERMOELECTRIC PROPERTIES OF TERNARY SOLID SOLUTIONS (Bi <sub>X</sub>Sb <sub>1</sub>_ <sub>X</sub>) <sub>2</sub>Te <sub>3</sub>
The purpose of this papers is to show the possibility of polycrystal thermoelectric material growing in the same cycle as a result of combining the operations of synthesis and fusion zone recrystallization without loss of thermoelectric quality factor. That end the low-temperature thermoelectric materials (Bi xSb 1-x) 2Te 3 were obtained in plant and laboratory conditions. Determination of composition and unit cell parameters by XRD methods showed that obtained materials are substitutional solid solutions. Obtained results shows that substitution of antimony by bismuth in the metal sublattice Sb 2Te 3 changes the parameter a of the hexagonal unit cell, whereas the parameter c remains unchanged practically. The atomic composition of laboratory and plant samples (Bi xSb 1-x) 2Te 3 determined by the a parameter values in accordance with Vegard’s law. Thermoelectric quality factor Z for obtained materials was determined by measuring three electrophysical values: the coefficient of thermal emf, electrical resistivity and thermal conductivity. Conclusions: The possibility of growing experimental samples in one cycle of the fusion of the charge calculated composition with an acceptable value of the quality factor ~ 2.5 • 10 -3 K -1, is practically identical with that of samples obtained in a plants as a result of successive operations of synthesis, cleavage and zone recrystallization.