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

We review our quantitative results related to the physical properties of me tallic nanoparticles that were obtained by time-resolved electron microscop y. These studies include the solid liquid transition and structural instabi lities. Surface melting has been demonstrated, quantitatively measured and analysed within the framework of a phenomenological model. The nature of th e liquid layer is discussed. Quantitative studies of the structural instabi lities indicate a spontaneous appearance of twin defects inside the nanopar ticles and their spontaneous disappearance. It has been found that this pro cess is thermally activated.