Hydrodynamic instability and self-organization of a submicron relief on metal surfaces upon femtosecond laser exposure in liquids

Multishot exposure of nickel and iron surfaces by loosely focused femtosecond laser pulses in isopropyl alcohol resulted in quasi-regular arrays of submicron spikes and other intermediate self-organized structures. Such self-organized surface relief is considered to be formed via hydrodynamic instability of molten metallic surfaces in their contact with a near-critical alcohol vapor layer with the pressure of about 5 MPa.