Shock compression of zirconia ZrO2 and zircon ZrSiO4 in the pressure range up to 150 GPa

Abstract

The shock compression state of zirconia ZrO2 and zircon ZrSiO4 in the pressure range up to 150 GPa (1.5 Mbar) are studied on the basis of the measurements of shock velocities, particle-velocity histories, free surface motions, and electrical conductivities. Zircon transforms, and zirconia probably does, to high pressure phases up to 90 GPa. The shock velocity (U s ) — particle velocity (U p ) Hugoniots can be described as U s =4.38+1.37 U p km/s above 90 GPa for ZrO2, and U s =6.50+0.49 U p km/s (mixed phase region), and U s =1.54+2.30 U p km/s (high pressure phase region) for ZrSiO4. The corrected isothermal densities of the high pressure phase ZrSiO4 are roughly consistent with the isothermal ones of mixtures of ZrO2 and SiO2. Bulk sound velocities in the high-pressure phase region of these oxides are discussed in comparison with other dioxides. Electrical conductivities of these oxides increase from lower than 10−12 S/m to greater than 100 S/m in the shock-stress range up to 70 GPa, and remain as constant values up to higher than 100 GPa.