FRIDAY, August 27, 2004
Time: 10:00 - 11:00 AM
Room: Constant Hall Room 1036

Dr. Yongwimon Lenbury
Mahidol University, Bangkok

One of the methods found suitable for predicting pattern selection in nonlinear phenomena is a weakly nonlinear stability analysis that, although incorporating the nonlinearities of the relevant model system, basically pivots a perturbation procedure about the critical point of linear stability theory [reviewed by Wolkind et al. (1994)]. The advantage of such an approach over strictly numerical procedures is that is allows one to deduce quantitative relationships between system parameters and stable patterns which are valuable for experimental design and difficult to accomplish using simulation alone. The development of spontaneous stationary equilibrium patterns on metallic or semiconductor solid surfaces during ion-sputtered erosion at normal incidence can be investigated by means of various weakly nonlinear stability analyses applied to the appropriate governing equation for this phenomena. In particular, the process can be represented by a damped Kuramoto-Sivashinsky nonlinear partial differential time-evolution equation for the interfacial deviation from a planar surface which includes a deterministic ion-bombardment arrival time and is defined on an unbounded spatial domain. Other applications shall be mentioned if time permits.