THERMAL AND ELECTRICAL CHARACTERIZATION OF (CDTE)(1-X)TE-X COMPOSITES- ELECTRON-PHONON SYSTEM

Citation
Me. Rodriguez et al., THERMAL AND ELECTRICAL CHARACTERIZATION OF (CDTE)(1-X)TE-X COMPOSITES- ELECTRON-PHONON SYSTEM, Materials letters, 36(1-4), 1998, pp. 95-101
Citations number
19
Categorie Soggetti
Material Science","Physics, Applied
Journal title
ISSN journal
0167577X
Volume
36
Issue
1-4
Year of publication
1998
Pages
95 - 101
Database
ISI
SICI code
0167-577X(1998)36:1-4<95:TAECO(>2.0.ZU;2-V
Abstract
Pressed discs of mixed powders of CdTe (semiconductor) and Te (semimet al) with different mass concentrations were thermally and electrically characterized. In this granular system: (CdTe)(1-x)Te-x, studied in t he entire range 0 less than or equal to x less than or equal to 1, whe re x is the fractional weight of Te, it has been found to exist a perc olation critical point, x(c) = 15.05%, for the electrical resistivity (rho), by showing an abrupt decreasing of six orders of magnitude (rho similar to 10(8) to rho similar to 10(2) Omega cm). The fractional we ight value of x(c) = 15.05% corresponds to a volumetric fraction of 15 .4%, according within the error scattering with the accepted theoretic al value of 16.0%, for a volumetric fraction at the critical percolati on in a three-dimensional system based in a mixture of conductive-insu lator materials. The study of the theoretical properties of the compos ite were reduced to the analysis of the thermal diffusivity (a), as th is is a dynamical property responsible for the establishment of the th ermal equilibrium in a given material. The experimental results show a complex dependence of ct as a function of the parameter x, evidencing a thermal transport influenced by an electron-phonon interaction. (C) 1998 Elsevier Science B.V. All rights reserved.