NONLINEAR RESONANCE STUDY OF THE PERIODIC MOTION OF THE EXPLOSIVE CRYSTALLIZATION FRONT IN GLASSES

The theoretical treatment of self-sustained periodic motion of the exp losive crystallization (EC) front in a thin amorphous film is presente d. The main attention is given to the study of nonlinear resonance phe nomena occurring due to the presence of a small external periodic pert urbation with the frequency being in the vicinity of the ordinary or p arametric resonance. Weakly anharmonic oscillations of the EC front ve locity are considered with the Van der Pole method, and the expression s for the limit cycle amplitude in the case of free and forced oscilla tions are derived. Depending on the values of kinetic and thermophysic al parameters of the model, different kinds of resonance curves (ie., front oscillation amplitudes versus frequency detuning) are obtained a nd analyzed. Our predictions may be tested experimentally by monitorin g the explosive growth rate using the modulation of laser intensity or employing amorphous films with thickness periodicity. It is also show n that inclusion of the results of dynamic stability analysis changes the steady-state EC stability diagram in the (T-s,d) plane (T-s is the substrate temperature and d the film thickness) so that the region of stable EC regimes becomes substantially more limited.