Elasticity of ω -phase zirconium

Compressional (VP) and shear wave (VS) velocities as well as unit-cell volumes of the ω phase of Zr have been measured at high pressure (6.9-10.9 GPa) at room temperature using ultrasonic interferometry in conjunction with synchrotron x radiation. Both VP and VS as well as the adiabatic bulk (KS) and shear (G) moduli exhibit monotonic increase with increasing pressure. Using a finite strain equation of state approach, the elastic bulk and shear moduli and their pressure derivatives are derived from the directly measured velocities and densities, yielding KS0 =104.0 (16) GPa, G0 =45.1 (9) GPa, K S0 ′ =2.8 (2), and G0′ =0.6 (1) independent of pressure calibration. The low pressure dependence of KS0 and G0 may be attributed to the pressure-induced progressive s-d electron transfer in the ω-Zr as suggested by previous Raman studies as well as static compressions at high pressure.