High-Pressure Elastic Properties of Vanadium: Insights from Ultrasonic Interferometry

Compressional (P) and shear (S) wave velocities of polycrystalline vanadium were measured simultaneously up to 11.5 GPa at room temperature using ultrasonic interferometry in a 1000-ton uniaxial split cylinder apparatus with a Walker-type multi-anvil module. Complex softening behavior in its S wave velocity and resulting shear moduli are revealed, possibly a precursor to the reported electronic topological transition at 30-60 GPa. By fitting the measured P and S wave velocities to the 3rd-order finite strain equations, the elastic bulk and shear moduli and their pressure derivatives were determined. The pressure-volume data derived from the current ultrasonic measurements are in good agreement with hydrostatic literature values. The current data not only enables a comprehensive assessment of vanadium's elastic and mechanical properties at high pressures, including bulk and shear moduli, Young's modulus, Poisson's ratio, and Pugh's ratio, but also these experimental results allow us to compare and benchmark the existing Steinberg-Guinan model for extrapolations to extreme pressure and temperature conditions.