10.6084/m9.figshare.1012510.v1 E Pedersoli E Pedersoli A J Nelson A J Nelson J Bozek J Bozek C Bostedt C Bostedt D Starodub D Starodub R G Sierra R G Sierra C Y Hampton C Y Hampton F Capotondi F Capotondi N D Loh N D Loh M Aslam M Aslam (a)–(c), (g)–(i) Selection of diffraction patterns and (d)–(f), (j)–(l) respective iterative phase-retrieval reconstruction of the real space image of clusters of Co@SiO<sub>2</sub> NPs irradiated with x-rays pulses of 777 eV photon energy IOP Publishing 2013 nanoparticle nm cdi laser diameter diffraction patterns Linac Coherent Light Source core understanding mesoscopic morphology pulse nanoparticulate matter Atomic Physics Molecular Physics 2013-08-13 00:00:00 Figure https://iop.figshare.com/articles/figure/_a_c_g_i_Selection_of_diffraction_patterns_and_d_f_j_l_respective_iterative_phase_retrieval_reconstr/1012510 <p><strong>Figure 3.</strong> (a)–(c), (g)–(i) Selection of diffraction patterns and (d)–(f), (j)–(l) respective iterative phase-retrieval reconstruction of the real space image of clusters of Co@SiO<sub>2</sub> NPs irradiated with x-rays pulses of 777 eV photon energy.</p> <p><strong>Abstract</strong></p> <p>Unraveling the complex morphology of functional materials like core–shell nanoparticles and its evolution in different environments is still a challenge. Only recently has the single-particle coherent diffraction imaging (CDI), enabled by the ultrabright femtosecond free-electron laser pulses, provided breakthroughs in understanding mesoscopic morphology of nanoparticulate matter. Here, we report the first CDI results for Co@SiO<sub>2</sub> core–shell nanoparticles randomly clustered in large airborne aggregates, obtained using the x-ray free-electron laser at the Linac Coherent Light Source. Our experimental results compare favourably with simulated diffraction patterns for clustered Co@SiO<sub>2</sub> nanoparticles with ~10 nm core diameter and ~30 nm shell outer diameter, which confirms the ability to resolve the mesoscale morphology of complex metastable structures. The findings in this first morphological study of core–shell nanomaterials are a solid base for future time-resolved studies of dynamic phenomena in complex nanoparticulate matter using x-ray lasers.</p>