EVIDENCE FOR CAPILLARY WAVES ON DEWETTED POLYMER FILM SURFACES - A COMBINED X-RAY AND ATOMIC-FORCE MICROSCOPY STUDY

Surfaces of thin dewetted polyethylene-propylene films were investigat ed by atomic force microscopy (AFM) and x-ray scattering. The AFM imag es show the mesoscopic island structure but do not give information ab out the microscopic roughness of the polymer surface. Together with th e AFM data we were able to identify capillary waves on the island surf aces by their specific power laws in the diffuse x-ray scattering sign al. The wave number spectrum of these waves is modified by a cutoff in troduced by the van der Waals substrate-film interactions. [S0031-9007 (98)07245-7].