Soft x-rays induce femtosecond solid-to-solid phase transition
  Soft x-rays were applied to induce graphitization of diamond through a non-thermal solid-to-solid phase transition. This process was observed within poly-crystalline diamond with a time-resolved experiment using ultrashort soft x-ray pulses of duration 52.5 fs and cross correlated by an optical pulse of duration 32.8 fs. This scheme enabled for the first time the measurement of a phase transition on a timescale of ~150 fs. Excellent agreement between experiment and theoretical predictions was found, using a dedicated code that followed the non-equilibrium evolution of the irradiated diamond including all transient electronic and structural changes. These observations confirm that soft x-rays can induce a non-thermal ultrafast solid-to-solid phase transition on a hundred femtosecond timescale. 
Franz Tavella, Hauke H\"oppner, Victor Tkachenko, Nikita Medvedev,   Flavio Capotondi, Torsten Golz, Yun Kai, Michele Manfre...
physics.atom-ph cond-mat.mtrl-sci