| SM ISO690:2012|
FREIK, D.; KRYSKOV, Ts.; LYUBA, T.; OPTASYUK, S.; RACHKOVSKY, O.; TSYKANIUK, B.. Temperature dependence of the Seebeck coefficient and electrical conductivity for compounds of system Pb-Ag-Sb-Te. In: Materials Science and Condensed Matter Physics. Editia a 7-a, 16-19 septembrie 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Fizică Aplicată, 2014, p. 112.
|Materials Science and Condensed Matter Physics
Editia a 7-a, 2014
Conferința "Materials Science and Condensed Matter Physics" |
Chișinău, Moldova, 16-19 septembrie 2014
Compounds based on PbTe are basic materials for modern thermoelectrics in the area of average temperatures (500-750 K). Undoped PbTe has a limited capacity for practical applications because of the low thermoelectric effectivity, therefore, appropriate to use solid solutions based on it for improving the thermoelectric parameters. PbTe-Sb2Te3 with impurity concentration of 1, 3, 5 ml. % and multicomponent compounds Pb18Ag1Sb1Te20, Pb18Ag0,5Sb1,5Te20, Pb18Ag1,5Sb0,5Te20 were synthesized. Previously cleaned Pb, Te and also Ag and Sb were used as starting components for the synthesis. For solid solutions PbTe-Sb2Te3 the compound Sb2Te3 was synthesized in advance. All materials were taken in purity B4 class, in stoichiometric ratio. The synthesis was held by direct fusion method with the mixing of the components in evacuated quartz ampoules. From the synthesized samples were formed compacts by grinding and pressing at pressure 0,2 GPa. Temperature dependences of the Seebeck coefficient and electrical conductivity were obtained by the standard method . The experimental results are shown in Fig.1. As shown in Fig. 1 temperature dependences for undoped PbTe have good agreement with literature . The introduction of Ag and Sb impurities in PbTe leads to changes in dependences (T) and (T). It should be noted that for Pb18Sb0,5Ag1,5Te20, where the relative silver content is maximum, the conductivity virtually unchanged, while the Seebeck coefficient monotonically decreases with increasing of temperature. The character of the temperature dependences for Pb18Sb1Ag1Te20 is significantly different, in the range (20-80) C linear increasing of conductivity observes, while the Seebeck coefficient does not change (curve 3) and changing of (T) and growth of (T) occurs in the temperature range (90-150) C. Thus, the temperature dependences of the Seebeck coefficient and electrical conductivity of the solid solutions Pb18Sb1Ag1Te20, Pb18Sb1,5Ag0,5Te20, Pb18Sb0,5Ag1,5Te20 are presented in this work. It is established, that the maximum value of Seebeck coefficient are observed for Pb18Ag1,5Sb0,5Te20, and conductivity - for Pb18Ag1Sb1Te20.