Femtosecond-Laser-Driven Shock Quenching of the High-Pressure Phase of Iron

Abstract

The quenching of the ε phase of iron, which has not been observed under a conventional shock compression, was attained using a femtosecond laser. The crystalline structure in a recovered iron sample was determined using an electron backscatter diffraction pattern method and an electron diffraction pattern method. A small quantity of the γ phase of iron also existed. Thermodynamic state inside the shock front has to be known because the shock induced phase transition occurs inside the shock front. Therefore, the temperature inside the shock front was calculated using thermodynamic equations. It was found that the ε phase was induced by the shock itself but not the γ phase. The γ phase was suggested to be induced as an intermediate structure between the α-ε transition. The femtosecond laser driven shock may have the potential to quench high-pressure phases which has not been attained using conventional methods.