Nanostructuration périodique et défauts induits par irradiation laser femtoseconde

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1 Nanostructuration périodique et défauts induits par irradiation laser femtoseconde Florence GARRELIE

2 Surface Structuration A universal phenomena. Ion beam Common feature: energy input auto-organization & periodicity Keller et al, Materials 2010 With a laser... Nanosecond Laser CO 2 Laser Keilmann Appl. Phys. A 1982 Femtosecond Laser Linear Polarisation Circular Polarisation 100 µm 5 µm 2 J. Reif et al, Phys. Stat. Sol. C 2009

3 Formation dynamics of LIPSS Low spatial frequency LIPSS: Perpendicular to E 600 nm period (several shots) Ultrafast irradiation: 100 fs duration < Fth pulses Absorbing material: Conditions for Surface Wave Excitation? Response time compatible with spatio-temporal ordering? Multiscale structuration

4 Formation dynamics of LIPSS E Origin : 2 main concepts Interference model and/or plasmon waves excitation Resonant in nature, inhomogeneous energy deposition Agree with the most observed orientation & period Dependence on laser fluence and pulse number Spatio-temporal ordering: spontaneous pattern formation Instability, positive feedback and exponential growth of initial perturbation Agree with periodicity dependence on Fluence/N Orientation and laser wavelength dependence? Hybrid nature Towards a unified approach

5 Formation dynamics of LIPSS Step by step formation Overview: Absorption stage Nonequilibrium energy distribution Hydrodynamic stage Positive feedback effects

6 Nanostructuration: A possible temporal schema Métal 0 Femtosecond Laser Photons- e - Absorption of photons by electrons of metal 100 fs Inverse Bremsstrahlung SP excitation Spatially modulated heating of the sample surface et al., Opt. Express, 19 (10), 9035 (2011)

7 Nanostructuration: A possible temporal schema Métal 0 Femtosecond Laser Photons- e fs Collisions (e-e) ps Electron-phonon Coupling High energy confinement High ripples contrast J.P. Colombier et al., J. Appl. Phys. 111, (2012)

8 Nanostructuration: A possible temporal schema Métal 0 Femtosecond Laser Photons- e fs ps < 1ns Electron-phonon Coupling Liquid Phase Thermocapillary force (Marangoni) High surface tension Low surface tension Hydrodynamic phenomena T 1 > T 2 γ(t 1 ) < γ(t 2 ) Flow from hotter to colder region

9 Nanostructuration: A possible temporal schema Métal 0 Femtosecond Laser Photons- e - Solidification 100 fs ps Electron-phonon Coupling < 1ns Liquid Phase

10 Nanostructuration: A possible temporal schema Métal fs Femtosecond Laser Photons- e - Plasmonic feedback : grating depth can change the surface wave dispersion ps Electron-phonon Coupling Cumulative Processes (N Laser shots) < 1ns Liquid Phase Resonance shifts toward a smaller periodicity for deeper gratings Solidification May influence the final morphology/periodicitiy J.P. Colombier et al, Journal of Laser Micro/Nanoengineering Vol. 7, No. 3, 2012

11 Experimental 11 Irradiations Laser Aspects fondamentaux AFM Topographie FEG-SEM / EBSD τ = 50 fs λ = 800 nm Gaussian beam profile 1 50 pulses Ni, Cr Polycristaux Monocristaux (100) (110) (111) 5µm Morphologie Orientation cristalline Défauts LGF FIB Cross-section HRTEM Microstructures Pt W Ni - LSFL 50 nm

12 Electron BackScatter Diffraction analysis Electron diffraction after scattering, diffraction (Kikuchi) bands viewed on p-screen Applications: crystal orientation, lattice deformation, various maps generation (100) 12 Probe e - Kikuchi lines (111) d hkl 2θ Plan (hkl) (111), deformed Phosphor screen High spatial resolution HR-EBSD : 20 nm x 60 nm x (10 to 50) nm

13 Cross-sectional study on LIPSS on metal 50µm Red mark indicates the area selected for cross-section extraction Inverse pole figure showing grain components at LIPSS and surrounding area Polycristalline Nickel Cross-section lamella chosen from a single grain A lamella (30x10x1µm) extracted by FIB lift-out process and welded on a Cu grid Cross-section surface milling after lift-out

14 LIPSS lamella Vacuum W 1µm 1µm 1µm Ni 0.4J/cm J/cm J/cm 2 2µm Local crystal disorientation map (LCD) to visualize small degree subgrain rotation Grain rotation revealed in LCD map can be used to analyze plastic deformation [1] A. Kumar, et al. JAP, 110 (2011)

15 Local crystal disorientation on LIPSS HR-Electron BackScattered Diffraction (EBSD) analysis 15 High fluence (0,4J/cm 2, with melting) up to 5-deg disorientation, mainly seen on the crests 1µm Local F = 0.4 J/cm 2 1 µm Medium fluence (0,24J/cm 2 ) disorientation distribution appears inhomogeneous, on the crests, in the valleys. Up to 2 deg 1µm Local F = 0.24 J/cm µm Low fluence (0,15J/cm 2 ) very thin layer with grain rotation 1µm Local F = 0.15 J/cm µm Sedao et al, Applied Surface Science 302 (2014) Legend of local disorientation map (in degree)

16 Crystal orientation and LIPSS formation: polycrystalline Ni Pt Ni [111] 200 nm (100) Cross-section STEM (111) Pt E Ni [100] 200 nm Cross-section STEM X. Sedao, et al Applied Physics Letters; 104, (2014) Competition between LIPSS formation and lattice defects storage - Laser induces more lattice damage on (111) - Higher degree of lattice mis-orientation 16

17 Different types of Periodic Surface Structures Orientations and periodicities Low-Spatial Frequency LIPSS Far-Field E Cr (100) 625 nm High-Spatial Frequency LIPSS LSFL Far-Field // 210 nm Pulse Number 30 Pulse duration 50 Wavelength 800 nm Near -Field // 120 nm HSFL Repetition rate 1 KHz Near-Field // 2 μm 50 nm H. Zhang et al. (Phys. Rev., 2015) A. Abou Saleh, to be published (2017)

18 High-Spatial Frequency Surface Nanostructures (HSFL) Ni (111) Near -Field // Pulse Number 46 Pulse duration 50 fs 1 µm ~90 nm 2 μm Wavelength Repetition rate Fluence 800 nm 1 KHz 0.19 focus on NF // structures J/cm 2 X. Sedao et al, ACS Nano 10, 6995 (2016)

19 Growth Twinning in Ultrafast Laser-Induced Transient Melting and Resolidification FCC metal (111) Ni Lattice distortions and defects revealed by EBSD map Cross-sectional study of Ni (111) crystal irradiated by 46 femtosecond (fs) laser pulses at a laser fluence of 0.19 J/cm 2 19 X. Sedao et al. (ACS Nano, 2016)

20 Growth Twinning due to Transient Melting and Resolidification 20 FCC metal (111) Ni Superimposed image in false colors Laminated epilayers of lattice Laminated twin layers X. Sedao et al. (ACS Nano, 2016)

21 Growth Twinning due to Transient Melting and Resolidification 21 FCC metal (111) Ni Atomistic simulation study of laser-induced defects Single green layer and double green layer => twin boundary and stacking fault in the fcc structure X. Sedao et al. (ACS Nano, 2016)

22 Different types of Periodic Surface Structures Orientations and periodicities 22 E Cr (100) 2 μm Pulse Number Pulse duration Wavelength Repetition rate nm 1 KHz Far-Field // 210 nm focus on FF // structures HSFL A. Abou Saleh, to be published (2017)

23 Crystal orientation dependence on LIPSS formation (FF//) FFT Cr (100) E ʌ = 220 nm FFT Pulse Number 2 Fluence 0.3 J/cm² Fluence range Between spallation and phase explosion Cr (110) E Formation of HSFL High dispersion FF // Inhibited HSFL formation Singular responses of the different crystalline orientations (110) less favorable to LIPSS formation 1 μm A pure roughness effect? 1 μm

24 Roughness formation (FF//) Cr (100) Cr (110) How was the surface after the 1 st pulse? Atomic Force Microscopy shows strong differences of sharpness Spiky surface Sku=5.6 Bumpy surface Sku=2 A. Abou Saleh et al, submitted to Appl. Phys. A (2017)

25 Crystal orientation dependence on LIPSS formation (FF//) Cr (100) Cr (111) Cr (110) Pulse Number 1 Fluence 0.3 J/cm² SEM micrograph Fluence range Between spallation and phase explosion Mean Angular Deviation Local Misorientation High plastic deformation and high density of dislocations on (110) orientation (110) Orientation more likely to get damaged

26 Influence of crystal orientation on defect formation 26 HAADF-TEM Analysis Cr (100) Pulse Number 1 Cr (110) Fluence Fluence range 0.3 J/cm² Between spallation and phase explosion Band contrast Band contrast Surface Surface 100 nm 100 nm Distorted layer of about 50 nm in depth on (110) orientation No marked contrast on (100) orientation

27 Crystal orientation dependence on LIPSS formation (FF//) HAADF-TEM Analysis 50 nm Surface Cr (110) Scattered intensity I Depth (nm) Scattered intensity I I α ZZ. ρ. V Z = Atomic number V = Probed volume ρ = Atom density 18 % in depth scattered intensity drop Generation of high density vacancies

28 Atomistic simulation study of laser-induced defects in BCC metal Pulse Number Fluence range 1 Between spallation and phase explosion Cr (100) Cr (111) Cr (110) Leonid Zhigilei Eaman Abdul-KArim Red atoms Free surface of the target Blue atoms Laser induced defects At the end of the simulation Dislocations propagate more deeply in (110) orientation 120 nm depth Dislocations appear below the melting front (rarefaction wave), during the resolidification process

29 Some applications Super-hydrophobic surfaces Information transport & optical technologies Marking for security applications Tribology of corrugated surfaces Colorized Silicon M.Groenendijk, Laser Technik Journal, 5 (3) (2008). H.D. Yang et al., Appl. Phys. A 104 (2011) Color coding and marking based on laser-induced nanostructures D. Quéré B. Dusser et al., Opt. Express 18 (2010)

30 Xxx SEDAO Anthony ABOU SALEH Stéphanie REYNAUD Florent PIGEON Jean-Philippe COLOMBIER Claire MAURICE² Thierry DOUILLARD 3 Claude ESNOUF 3 Univ Lyon, UJM-Saint-Etienne, CNRS, IOGS, Laboratoire Hubert Curien, UMR5516, St-Etienne ² Ecole des Mines de Saint-Etienne, Laboratoire Georges Friedel, CNRS, UMR5307, St-Etienne 3 Univ Lyon, INSA Lyon, CNRS, MATEIS, UMR 5510, Villeurbanne

31 Thank you for your attention