2004 Volume 45 Issue 12 Pages 3309-3313
Rapidly solidified bismuth-telluride based alloy foil; fabricated using the single roller melt spinning method exhibits a fine microstructure with unidirectional crystals. Meanwhile, a hot-pressing process, using rapidly solidified foils, was used to prepare the consolidated samples. The fine microstructure of this alloy is extremely effective in decreasing thermal conductivity because of the grain boundary scattering of the phonons, a key factor improving the thermoelectric properties of thermoelectric materials. Hot-pressed samples using these rapidly solidified foils display lower thermal conductivity values than the alloys made by the conventional hot-consolidating method using pulverized ingot powder. In this case, thermoelectric properties were investigated comparatively in terms of hot-pressed rapidly solidified foil specimens and pulverized powders of these foils under 53 μm in size, evaluating the dependence of the hot-pressing temperature and consequent pressure on the thermoelectric properties of these specimens. The maximum figure of merit (Z) obtained was 3.34 × 10−3 K−1.