High-pressure phase synthesis of Si using femtosecond laser-driven shock wave

High-pressure phases of silicon are synthesized using femtosecond laser-driven shock wave. The crystalline structure in a recovered sample was determined using synchrotron x-ray diffraction and electron diffraction methods. The high- pressure phase with simple hexagonal structure exists in the recovered sample. The metastable BC8 structure also exists. The temperature profile in the shock wave as a function of the pressure was estimated using the thermodynamic theory. The estimated results agree well with the experimental results.