Time-resolved electron microscopy studies of the structure of nanoparticles and their melting

We review our quantitative results related to the physical properties of metallic nanoparticles that were obtained by time-resolved electron microscopy. These studies include the solid liquid transition and structural instabilities. Surface melting has been demonstrated, quantitatively measured and analysed within the framework of a phenomenological model. The nature of the liquid layer is discussed. Quantitative studies of the structural instabilities indicate a spontaneous appearance of twin defects inside the nanoparticles and their spontaneous disappearance. It has been found that this process is thermally activated.