Pressure-dependent Hugoniot elastic limit of Gd₃Ga₅O₁₂ single crystals

Single-crystal Gd₃Ga₅O₁₂ has been studied at high dynamic pressures generated with plate impacts. Shock-wave profiles and Hugoniot points were measured with a picosecond time-resolved Doppler Pin System. For final shock pressures in the range 8.52-113 GPa, a two-wave structure is observed below 59.3 GPa, a three-wave structure at ∼88.5 GPa, and a single shock wave is observed at ∼113 GPa. Our data show that the Hugoniot elastic limit (HEL) of single-crystal Gd₃Ga₅O₁₂ is strongly dependent on final shock pressure. The HEL increases from 7.65 to 24.2 GPa as final pressure increases from 8.52 to 88.5 GPa. A shock-induced phase transformation is observed at a pressure of ∼75.9 GPa, which is a little higher than the value reported previously (Mashimo et al., Phys. Rev. Lett. 96, 105504, 2006), but is consistent with previous DAC work (Mao et al., Phys. Rev. B 83, 054114, 2011).