The high-temperature elastic moduli of polycrystalline PbTe measured by resonant ultrasound spectroscopy

The thermoelectric material PbTe has been used in a wide variety of power generator applications. However, there is limited mechanical property data available for PbTe for temperatures above room temperature. This paper reports dynamic elastic moduli measured via resonant ultrasound spectroscopy on undoped and PbI2-doped polycrystalline PbTe between room temperature and 773 K; in addition, the room temperature carrier concentration was measured by a Hall effect experiment. The Young’s modulus and shear modulus of PbTe decreased linearly with temperature above room temperature, while the Poisson’s ratio exhibited either monotonic increase or decrease with temperature. The Young’s modulus and shear modulus values obtained during heating and cooling agreed to within 1%. The dynamic elastic moduli data obtained in this study compared well in general with literature data. The difference observed between the current study and other literature studies is explained in terms of the carrier concentration effect on elastic moduli.