Lyapunov exponent as an indicator of phase transition in melting Pd-13 clusters

Abstract

In this study, the chaotic behaviour of Pd13 clusters is investigated in a wide total energy range. To identify interactions between atoms, the embedded atom potential is used in the computer simulation. Various analyses including power spectra, maximal Lyapunov exponents (lambda) and rms bond-length fluctuations (delta) are carried out to identify the characteristics of the system. As a result of these analyses, it is observed that Lyapunov spectra can clearly indicate the co-existence region for Pd-13 clusters and exponents have fixed values above a certain total energy value of the system. In addition, while the fast Fourier transforms give the existence of diffusive motion above the transitional region, the correlation dimension values exhibit a smooth character relevant to the total energies of the system.