Phase transition as a relaxation from shear stress in uniaxial compression*

In well-known phase transition mechanism under laser shocked material, highly and elastically strained lattice would be relaxed by plasticity as pressure inside of material exceeds Hugoniot Elastic Limit (HEL). Then phase transition to higher pressure state would come after the plastic deformation if enough pressure is given. In different phase transition mechanism we will present, highly strained lattice would be relaxed by transition itself, and requires lower laser energy and shorter transition time to synthesize higher pressure state. We would like to introduce this mechanism through the X-ray Free Electron Laser (XFEL) observation of phase transition in carbon materials.