Direct observation of structural transitions in laser-shocked Zr by means of time resolved XAS

The conditions and mechanisms reported for the pressure-induced alpha-omega phase transformation in zirconium are different under static and dynamic loading. In a previous work (HC-1607), we have studied this phase transition using a dynamic hydrostatic compression setup involving a dynamic Diamond Anvils Cell (DAC) coupled with ms-scale time-resolved X-ray Absorption Spectroscopy (XAS). The dynamic transition pressure measured at 12±1 GPa was similar to that observed under static hydrostatic compression, but the transition time was found to be less than 2 ms, in contradiction with earlier results which reported a sluggish kinetics, with transformation times reaching several minutes. In this work, we would like to address the same problem at the ns time scale, using laser shock compression coupled with ps time-resolved XAS measurements.