Formation of the Submicron Oxidative LIPSS on Thin Titanium Films During Nanosecond Laser Recording.

Dmitry A Sinev,Vadim P Veiko,Mikhail K Moskvin,Daria S Yuzhakova

doi:10.3390/nano10112161

Abstract

Laser-induced periodic surface structures (LIPSSs) spontaneously appearing on the laser-treated (melted or evaporated) surfaces of bulk solid materials seem to be a well-studied phenomenon. Peculiarities of oxidative mechanisms of LIPSS formation on thin films though are far less clear. In this work, the appearance of oxidative LIPSSs on thin titanium films was demonstrated under the action of commercially available nanosecond-pulsed Yb-fiber laser. The temperature and energy regimes favoring their formation were revealed, and their geometric characteristics were determined. The period of these LIPSSs was found to be about 0.7 λ, while the modulation depth varied between 70 and 110 nm, with high stability and reproducibility. It was shown that LIPSS orientation is rather easily manageable in the regimes of our interest, which could provide a way of controlling their properties.

Highlights

The formation of laser-induced periodic surface structures (LIPSSs), which was observed on a wide range of materials under the action of laser radiation, is a well-known phenomenon that attracts both fundamental and applied attention in modern photonics
The formation of oxidative LIPSSs in [12,14,22] can be represented as the result of the interference of the incident laser radiation, with that scattered by the initial film roughness
We present experimental results showing that regular oxidative LIPSSs, which have not been previously observed in the range of low-temperature processes on thin titanium films, can be obtained under the action of nanosecond laser pulses

Summary

Introduction

The formation of laser-induced periodic surface structures (LIPSSs), which was observed on a wide range of materials under the action of laser radiation, is a well-known phenomenon that attracts both fundamental and applied attention in modern photonics. A significant number of studies have been devoted to the study of LIPSSs appearing under pico- and femtosecond laser exposure [4,9,10,11], often localized in small areas of the irradiated region. In [14], LSFLs were obtained on a Cr film under femtosecond exposure to Yb:KGW laser radiation (wavelength 1026 nm, pulse duration 232 fs) in a nondestructive regime. Those structures, significantly protruded above the surface of the initial film, which according to the authors indicated the significant oxidation of the irradiated metal in the areas of the protrusions

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Results

Conclusion