THERMODYNAMİC PROPERTİES OF THE Bi2Te3 AND Bi4Te5 COMPOUNDS

Abstract

The thermodynamic properties of the BiTe system were studied in the 55-65 at% Te compositions interval and temperatures 300-450 K by using the electromotive forces method. Relative partial molar functions of bismuth in the alloys were calculated. Based on the potential-forming reactions for Bi 2 Te 3 and Bi 4 Te 5 compounds, a mutually consistent set of standard thermodynamic functions and standard entropies is obtained. A comparative analysis of the data obtained for Bi 2 Te 3 with literature is performed, for Bi 4 Te 5 thermodynamic functions were obtained for the first time.

Thermodynamıc Propertıes of the BiTe and Bi8Te9 Compounds

“…the standard thermodynamic functions of the formation of Bi8Te9 and BiTe were calculated. In the relations (8) and (9) Z  G or H. For the calculations, we used the thermodynamic data [30] for Bi4Te5 (Table 3) as well as…”

“…In all cases, the estimated standard uncertainties were calculated by accumulating the errors. In Table 3, in addition to the results of the present work, the result of previous work [30] and literature data for BiTe are also presented. As can be seen from Table 3, the standard enthalpy of formation and entropy of BiTe determined by us is in good agreement with the data [21] and differ significantly from the results of [44] obtained by high temperatures EMF measurements.…”

“…The thermodynamic functions of Bi8Te9 were determined by us for the first time. A comparative analysis of our and published data for Bi2Te3 compound was performed in [30].…”

“…In [29], a new refined phase diagram of this system in the composition range of  60 at% Te is presented, and the formation of some bismuth tellurides with incongruent melting was shown. The thermodynamic functions of Bi2Te3 and Bi4Te5 compounds obtained by the method of electromotive forces (EMF) are presented in [30].…”

MULTI-3D MODELING OF PHASE DIAGRAM OF PbTe-Bi2Te3-Sb2Te3 SYSTEM

“…The analytical method, tested in [29][30][31], was used for the three-dimensional modeling of crystallization surfaces in the PbTe-Bi 2 Te 3 -Sb 2 Te 3 system. For 3D modeling of crystallization surfaces of phases the following equation was used:…”