Successful real-time observation of atomic motion with sub-nanometer resolution
Researchers have succeeded in using the immensely powerful X-ray pulses from the free electron laser (XFEL) facility SACLA to investigate excited-state induced transient lattice dynamics on sub-picosecond time scales in phase-change materials via X-ray diffraction. Phase-change materials (PCM) are broadly used in the current generation of rewritable DVD media as well as serving as the basis for nonvolatile phase-change random access memory (PC-RAM) widely believed to the successor to FLASH memory. The XFEL SACLA produces extremely bright and short intense (10 fs) pulses in the X-ray region and is the first domestic X-ray laser source in Japan. The ultrashort nature of the X-ray pulses in conjunction with their short wavelength (10-10 m) allow direct stroboscopic observation of transient changes in the atomic structure of solids on unprecedented time scales.