Fractal, linear, and non-linear optical properties of Mn-based complex star-shaped nanostructureMahsa Fakharpour and Hamid Akherat DoostEur. Phys. J. Spec. Top., 234 14 (2025) 3497-3508DOI: https://doi.org/10.1140/epjs/s11734-025-01655-3