Figure 3
Temporal evolution of the lattice spacing d and the corresponding elastic strain εe for a shock-compressed bcc (110) plane. Lattice spacing d (blue dots) and the corresponding compressive elastic strain εe are shown. Error bars for the lattice spacing indicate the full width at half maximum (FWHM) of the Bragg peaks for the shock-compressed bcc (110) plane. The d-spacing increases at τ = 10 ps, presumably due to lattice expansion caused by the rapid energy transfer from the electrons in the higher energy state due to inverse bremsstrahlung to the lattice. The lattice spacing decreases drastically to 1.88 Å at τ = 50 ps, corresponding to an elastic strain εe of 7.19% at a compressive strain rate of 1.96 × 109 s−1. After τ = 50 ps, the lattice spacing starts to expand. The expansion rate is initially high (− 4.05 × 108 s−1 for 50 ps ≤ τ ≤ 150 ps), while it becomes moderate after 150 ps (− 9.29 × 106 s−1 for 150 ps ≤ τ  ≤ 1 ns). The FWHM, which reflects the plasticity, increases between τ = 50 ps and 150 ps and then gradually decreases.
