Initial Morphology and Feedback Effects on Laser-Induced Periodic Nanostructuring of Thin-Film Metallic Glasses

Abstract

Surface nanostructuring by femtosecond laser is an efficient way to manipulate surface topography, creating advanced functionalities of irradiated materials. Thin-film metallic glasses obtained by physical vapor deposition exhibit microstructures free from grain boundaries, crystallites and dislocations but also characterized by a nanometric surface roughness. These singular properties make them more resilient to other metals to form laser-induced nanopatterns. Here we investigate the morphological response of Zr65Cu35 alloys under ultrafast irradiation with multipulse feedback. We experimentally demonstrate that the initial columnar microstructure affects the surface topography evolution and conditions the required energy dose to reach desired structures in the nanoscale domain. Double pulses femtosecond laser irradiation is also shown to be an efficient strategy to force materials to form uniform nanostructures even when their thermomechanical properties have a poor predisposition to generate them.

High-Density Nanowells Formation in Ultrafast Laser-Irradiated Thin Film Metallic Glass

“…High roughness promotes the appearance of large periodic structures with many irregularities and bifurcations. Working with a very smooth surface state with low roughness is thus suitable for creating self-organized multi-scale structures under optimal conditions [ 45 ]. The fluence conditions used for this work are below the single shot damage threshold found for the TFMG, from 0.04 to 0.07 J cm −2 .…”

Editorial: Special Issue “Laser-Generated Periodic Nanostructures”

“…We aimed to attract both academic and industrial researchers in order to collate the current knowledge of nanomaterials and to present new ideas for future applications and new technologies. By 8 August 2021, 22 scientific articles have been published in the Special Issue [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], see .…”

“…Three “Feature Papers” [ 15 , 16 , 17 ] were invited by the Guest Editors for the adequate framing of this Special Issue. An additional 19 papers were published as regular contributions [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. The publications in this Special Issue can generally be divided into three groups: (1) manuscripts related to self-organized laser-induced periodic surface structures [ 15 , 18 , 19 , 21 , 23 , 24 , 25 , 26 , 28 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], (2) manuscripts related to interference-based periodic surface structuring [ 17 , 22 , 27 , 29 ], or (3) manuscripts combining both approaches [ 16 , 20 ].…”

“…Several publications focus on the relevance of chemical surface alterations during or after laser-processing, including studies of superficial oxidation on the formation of specific types of LIPSS [ 18 , 23 , 24 , 25 , 30 ], chemo-capillary effects in DLIP [ 29 ], or even post-laser irradiation effects due to reactions with the environment [ 30 ]. Other publications study the fundamental mechanisms of structure formation on the basis of experimental and theoretical plasmonic approaches [ 15 , 21 , 26 ], and also in combination with a two-temperature model [ 28 ], advanced molecular dynamics simulations [ 22 ], or multi-physical hydrodynamic continuum considerations [ 31 , 34 ]. Two articles investigate in vitro the growth of different types of biological cells (either scar-forming fibroblasts or bone-forming osteoblasts) on laser-generated micro- and nanostructures for medical applications [ 19 , 25 ].…”

“…Prudent et al [ 34 ] experimentally studied the fluence- and pulse number-dependent evolution of surface morphology and the influence of interpulse feedback effects on the formation of LIPSS (LSFL and HSFL) on thin metallic glass (Zr 65 Cu 35 alloy) films on silicon—starting with different film-specific nanosized precursor structures (referred to as coarse and tight columns) and subsequently irradiating them with multiple (up to 50) sequences of single or parallel-polarized double-fs laser pulses (800 nm, 60 fs) in the interpulse delay range up to 70 ps. The authors suggest that the high viscosity of an amorphous alloy can be bypassed through double-fs-pulse irradiation that drives the material towards higher temperatures and lower viscosities—a state that is more favorable to it undergoing capillary melt flows.…”