Transient melting of a nanocrystal: seeing is believing

Scientists have discovered a spectacular transient melting phenomenon in nanocrystals. Coherent X-ray diffraction experiments have allowed snapshot imaging of a single 300 nm gold nanocrystal in the picosecond time interval after the particle was excited with a laser. The crystal was found to expand uniformly following the excitation and to reach the melting point about 50 ps later.