Mechanical reliability, thermal stability and thermoelectric performance of the transition-metal nitride CrN

The mechanical reliability and thermal stability of thermoelectric materials are often the most neglected, while they will greatly affect the reliability and performance of thermoelectric devices when used in extreme environments. In this study, a nanostructured chromium nitride (CrN) thermoelectric material with a ZT value ∼0.12, exhibiting both high mechanical reliability and thermal stability, was prepared using a simple chemical method. Its hardness, reaching 7.21 GPa, is much higher than that of most other traditional thermoelectric materials. Thermogravimetric analysis shows that CrN remains stable at 873 K. Moreover, friction and wear tests demonstrate the high wear resistance and low friction coefficient (∼0.42) of CrN. The high thermal stability and good mechanical properties are expected to offer a wide range of opportunities for the thermoelectric application of CrN in some extreme environments, such as collision avoidance systems and outer space.