Tracking of individual nanocrystals using diffracted x rays

We demonstrated dynamical observation of an individual nanocrystal in supercooled liquid water with the guidance of x-ray diffracted spots from the nanocrystal itself. This new system, which we call diffracted x-ray tracking, monitored small Brownian motions $(D=0.68\mathrm{}{\mathrm{mrad}}^2/\mathrm{s}$ at 233 K) of a single nanoparticle in real time and real space.