Coefficient of Thermal Expansion and Dynamic Response to Pulsed Energy Deposition in HfO ₂ ‐TiO ₂ Compositions

The coefficient of thermal expansion and the dynamic response to pulsed energy deposition were investigated in the 25 to 60 mol% TiO 2 region of the system HfO 2 ‐TiO 2 . Thermal expansion results revealed very low coefficients (≅1 × 10 −6 /°C) for the 30 to 40% compositions and relatively high coefficients (≅3 × 10 −6 /°C) for the 45 to 60% TiO 2 compositions. The 25% TiO 2 composition fell between these two groups. Dynamic response measurements revealed considerably lower free surface velocities for the 30 to 40% TiO 2 compositions than for the 45 to 50% TiO 2 compositions. Calculation of Grueneisen parameters, using the thermal expansion and dynamic response data, revealed low values for the 30 to 40% TiO 2 compositions and an increase by a factor of 2 to 3 for the 45 and 50% TiO 2 compositions.