Advances in high temperature Resonant Ultrasound Spectroscopy

Determining temperature-dependent elastic properties is powerful tool to study thermodynamics and material kinetics. Because elastic moduli are fundamental thermodynamic susceptibilities they connect directly to thermodynamics, electronic structure, and mechanic properties. Elastic moduli can be extracted using a technique called Resonant Ultrasound Spectroscopy (RUS).

RUS obtains elastic moduli from the mechanical resonant frequencies of a sample with a well-characterized shape while assuming free resonance conditions. To measure the mechanical resonance, a sample is typically held between ultrasonic transducers in contact with the sample.

The ability to perform RUS and characterize elastic properties across a wide range of temperature is essential to understand different phases, their stability as well as to study the internal stresses and annealing of defects. At high temperatures, the performance and stability of the transducers and electrical connections can be affected, so alternative ways to sense the sample resonances are needed. We show two new RUS capabilities that operate up to 900K and 1300K. We will show results on different materials, and materials where we determine phase and defects stability.