<p>➀ This research investigates how metallic thin films, specifically cobalt layers used in hard disk drives (HDDs), can be modified to improve performance and reliability through plasma-assisted surface modification techniques.</p><p>➁ The study uses molecular dynamics (MD) simulations and experimental validation to demonstrate how different inert gas ions affect asperity size and surface texture.</p><p>➂ The findings suggest that heavier inert gas ions are more effective at reducing asperity size, with Xenon (Xe) providing the most pronounced smoothing effect.</p>