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

Compressional (VP) and shear (VS) 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 VS and resulting shear moduli are revealed, possibly a precursor to the reported electronic topological transition at 30-60 GPa. The current data 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. Through fitting to the 3rd-order finite strain equations, the elastic moduli and their pressure derivatives were determined. Data were also fit to a Birch–Murnaghan equation of state, in agreement with hydrostatic literature values. These experimental results allow us to compare with and benchmark the existing Steinberg-Guinan model for extrapolations to extreme pressure and temperature conditions.