In order to grasp the various thermal properties for the thermoelectric materials such as Bi_2 Te_3 and PbTe, the novel technique has been developed using an identical specimen with the unchanged experimental set-up. The new design principle based on Angstrom's method employs the as heat source to give a specimen the periodical temperature oscillation and its phase shift. Since the dc one is also still available, it is feasible to perform the combination and simultaneous measurement of thermals diffusivity a and heat capacity c_p as well as thermal conductivity k. Actually, the measurements were carried out sing a transparent quartz glass, which is commonly used as reference material in measuring k for thermoelectric materials especially for Bi_2Te_3 materials. a obtained is in quite good agreement with the literature value at room temperature. Also by the aid of c_p-values obtained through ac calorimetric method the validity and reliability of temperature dependence of a was verified.
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