Multifractal analysis of sputtered CaF2 thin films

The surface morphologies of CaF2 thin films prepared by electron beam evaporation technique were measured by atomic force microscopy. The films were bombarded by energetic ion beams of different fluences, which modified the surface morphology predominantly via the process of erosion. The dependence of the surface morphology on ion fluence was explored using multifractal analysis. It was found that the roughness of the film first decreased with ion fluence but increased at higher fluences. Copyright © 2013 John Wiley & Sons, Ltd.