Thermal properties of clustered systems of mixed composition: the temperature response of Si–Al clusters studied quantum mechanically

This work has been undertaken with the purpose of extending the study of the thermal properties of nanosized systems beyond the mono-elemental cases so far considered. The structures adopted to this purpose consist on small columnar silicon clusters covered on both sides by an aluminum overlayer and have therefore to be regarded as the finite-size analogous of macroscopic electronic devices. The thermal response of these structures is evaluated under dynamical conditions and the transient is generated by increasing the overall kinetic energy in the system. The calculations are based on real-time, real-space implementations of the semiempirical Hartree–Fock and Density Functional theories. The results show the occurrence of phenomena similar to recristallization and melting in the bulk and illustrate the dependence of these effects on the cluster size and composition.