NOVEL THERMOELECTRIC-MATERIALS

Several new approaches to the design of improved thermoelectric materi als have stimulated a resurgence of interest in this very old field. W ithin the past two years materials have been developed that validated one or more of these new ideas. Perhaps the most significant developme nt is the concept and realization of materials that conduct electricit y like a crystalline solid but heat like a glass. In these materials a weakly bound atom or molecule 'rattler' is used to lower the thermal conductivity of the solid without severely affecting electronic conduc tion, thus leading to improved thermoelectric efficiency.