Dergiler / Turkish Journal of Physics / 1999 / Cilt: 23 - Sayı: 6
Electronic and Lattice Thermal Conductivity of Bi1-x Sbx and Ag-Sb-Te Systems
- Sayfa
- 977–984
- DOI
- —
Özet
An investigation of the electronic (\alephe) and lattice (\alephL) parts of the thermal conductivity for samples of Bi1-x Sbx (0,02 < X < 0,12) and system of Ag-Sb-Te was carried out in the temperature interval 6-300K. Separation of \alephL and \alephe has been made by suppressing \alephe in magnetic field. The experimental data of \alephL and \alephe have been compared, respectively, with Gallaway's theory and with a theory which takes into account the inelastic character of scattering. It is observed that the Lorentz number L calculated by using the experimental values of \alephe and thermomagnetic coefficients is smaller than its Zommerfeld's value L0 in high doping Bi0.88Sb0.12. A satisfactory agreement between the theory and the experiment allows to conclude that besides the normal and U-processes in Bi1-xSbx the defects of mass also plays a considerable role in scattering. It is observed that \alephL of single phase samples Ag0.82Sb1.18Te2.18 is smaller than AgSbTe2 samples. It is shown that this is due to the presence of p-Ag2 Te in AgSbTe2. It is established that the high concentration of intrinsic defects plays a considerable role in scattering for Ag-Sb-Te as well.
Abstract
An investigation of the electronic (\alephe) and lattice (\alephL) parts of the thermal conductivity for samples of Bi1-x Sbx (0,02 < X < 0,12) and system of Ag-Sb-Te was carried out in the temperature interval 6-300K. Separation of \alephL and \alephe has been made by suppressing \alephe in magnetic field. The experimental data of \alephL and \alephe have been compared, respectively, with Gallaway's theory and with a theory which takes into account the inelastic character of scattering. It is observed that the Lorentz number L calculated by using the experimental values of \alephe and thermomagnetic coefficients is smaller than its Zommerfeld's value L0 in high doping Bi0.88Sb0.12. A satisfactory agreement between the theory and the experiment allows to conclude that besides the normal and U-processes in Bi1-xSbx the defects of mass also plays a considerable role in scattering. It is observed that \alephL of single phase samples Ag0.82Sb1.18Te2.18 is smaller than AgSbTe2 samples. It is shown that this is due to the presence of p-Ag2 Te in AgSbTe2. It is established that the high concentration of intrinsic defects plays a considerable role in scattering for Ag-Sb-Te as well.