ICT2014 Abstracts

The Half-Heusler compounds are one of the most promising candidates among the mid-temperature to high-temperature thermoelectric materials being investigated for automotive and industrial waste heat recovery applications. For n- as well as p-type materials ZT values with peak values larger than one have been published recently and first modules have been built.

We will give an overview about our recent investigations about phase separation in the thermoelectric Heusler compounds. We will shortly present our studies on the phase separations in the quasi-ternary system TiNiSn-ZrNiSn-HfNiSn. Studying patents and publications the last two years carefully one could read a lot about not-single phase samples inside of the TiNiSn-ZrNiSn-HfNiSn system. Furthermore, we will show how we adapted this knowledge to design a p-type Heusler compound which led to a ZT increase of 50% compared to the best published bulk p-type Heusler compound in the literature.

Additionally, we will present how we used the knowledge about the phase separation to design thermoelectric highly efficient nano-composites of different single-phase materials.

These results strongly underline the importance of phase separations as an important tool in the design of highly thermoelectric efficient materials which fulfill the industrial demands for a thermoelectric converter.