Evolution of fractal dimension in pulsed laser deposited MoO${}_3$ film with ablation time and annealing temperature

The multifractal analysis is a potential method for assessing thin film surface morphology and its changes due to different deposition conditions and post-deposition treatments. In this work, the multifractal analysis is carried out to understand the surface morphology - root mean square (RMS) surface roughness - of nanostructured MoO${}_3$ films prepared by pulsed laser deposition technique by varying the ablation time and post-deposition annealing. The XRD analysis shows the evolution of crystalline nature with annealing temperature. The XRD pattern of all the annealed films shows the characteristic peak of the orthorhombic MoO${}_3$ phase. The FESEM and AFM analysis reveals the morphological modification with ablation time and annealing temperature. The multifractal analysis of the AFM images shows that the box - counting, information and correlation dimension varies with the annealing temperature. The study also reveals the inverse relation between the fractal dimension and the RMS surface roughness due to the annealing induced particle size variation and reorientation. The fractal dimension's evolution in the pulsed laser deposited MoO${}_3$ film with ablation time and annealing temperature is also investigated. Thus, the study reveals the potential of multifractal analysis in the thin film surface characterization.