ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The Seebeck coefficient, electrical resistivity, and thermal conductivity of La3−xAxS4 with the Th3P4-type structure (the γ-phase) for A=Ca, Ba, and x=0–0.8 have been measured as a function of alkaline earth metal content and temperature to determine the optimum dopant concentration and doping agent by calculating the corresponding figure of merit (Z). With an increase of x, the Seebeck coefficient and electrical resistivity increase, while the thermal conductivity decreases. The decrease of thermal conductivity is ascribed to the decrease of the electron concentration and the increase of the phonon scattering accompanying the substitution for La by an alkaline earth metal. As a result, La2.2Ca0.8S4 has a maximum value of Z of 2.3×10−4 °C−1 at 700 °C. We also have examined the long term stability of γ-La3−xAxS4. The substitution for La by alkaline earth metal of La3S4 stabilized the Th3P4-type structure at high temperature. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.366409
Permalink