文档介绍：Abstract
The efficiency of a TE device can be defined by the dimensionless thermoelectric figure of merit , ZT = S2·ς·T/κ,Where S stand for the See
beck coefficient, σ is the electrical conductivity and κ represent the total thermal conductivity. At the same time, σS2 characters the electric properties.
Skutterudite (CoSb3) materials have attracted wide attention since it was proposed. The methods at ambient pressure have many limits to prepare Skutterudite (CoSb3) materials, because it is a process of Peritectic conver sion. But the method of High-Pressure and High-Temperature has many advantages in the preparation of materials. In this study, we prepared thermoelectric materials by HPHT method and quenching method. First of all, we synthesized CoSb3 pounds by High-Pressure and High-Temperature technique. The samples were characterized by X -ray diffraction, which indicated that Polycrystalline Skutterudite with a bcc crystal structure was prepared. The SEM indicated that the samples have abundant grain boundaries and the crystal grain sizes vary between 1-2um.
Secondly, we prepared the system Co at many pressure points at the fundament of pure CoSb3 skutterudite. The electrical resistivities, Seebeck coefficients and power factor of the samples were measured in the room temperature. The thermoelectric properties of the samples were measured in the temperature range of 300-743 K. The power factor is increasing with
increasing temperature. The highest power factor of W·cm-1·K-2 was
obtained at 743K. The thermal conductivity of samples decreased with increasing of temperature. The lower samples’ thermal conductivit y ·m-1·K-1 was obtained at 743K. Ultimately, we calculate the material ZT of at a temperature of 743K. The tellurium replacement can effectively reduce the materials resistivity and thermal conductivity, and ultimately enhance the value of the thermoelectric figure of merit of the material. We can conclude that chemical d