Structural fluctuations in small particles

Abstract

We present a theoretical analysis of a phenomenon recently observed by high-resolution electron microscopy that involves rapid structural fluctuations in small f.c.c. particles below 10 nm in size. The different energy contributions to the total energy of the particle and the magnitude of the potential energy barrier between different shapes is evaluated and compared with the available energy during particle-beam interactions. The results indicate that the activation energy barrier existing between different shapes is only a few electron volts, whilst a rough estimate indicates that during electron-beam irradiation the available energy may be as much as 100–1000eV.