Basic investigations for laser microanalysis: IV. The dependence on the laser wavelength in laser ablation

1992 ◽  
Vol 108 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Wolfgang Sdorra ◽  
J�rgen Brust ◽  
Kay Niemax
Keyword(s):  
Laser Ablation ◽  
Laser Wavelength ◽  
Laser Microanalysis

scholarly journals Synthesis of Supported Heterogeneous Catalysts by Laser Ablation of Metallic Palladium in Supercritical Carbon Dioxide Medium

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5807
Author(s):  
Oleg Parenago ◽  
Alexey Rybaltovsky ◽  
Evgeniy Epifanov ◽  
Andrey Shubnyi ◽  
Galina Bragina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Laser Ablation ◽  
Supercritical Carbon Dioxide ◽  
Heterogeneous Catalysts ◽  
Mixing Time ◽  
Laser Wavelength ◽  
Process Conditions ◽  
Metallic Palladium ◽  
Palladium Particles ◽  
Supercritical Carbon

To obtain a supported heterogeneous catalyst, laser ablation of metallic palladium in supercritical carbon dioxide was performed in the presence of a carrier, microparticles of γ-alumina. The influence of the ablation process conditions—including supercritical fluid density, ablation, mixing time of the mixture, and laser wavelength—on the completeness and efficiency of the deposition of palladium particles on the surface of the carrier was studied. The obtained composites were investigated by scanning and transmission electron microscopy using energy dispersive spectroscopy. We found that palladium particles were nanosized and had a narrow size distribution (2–8 nm). The synthesized composites revealed high activity as catalysts in the liquid-phase hydrogenation of diphenylacetylene.

Laser Ablation of Machined Wood Surfaces. 2. Effect on End-Grain Gluing of Pine (Pinus silvestris L.)

Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 655-661 ◽  
Author(s):  
Micael Stehr
Keyword(s):  
Boundary Layer ◽  
Laser Ablation ◽  
Joint Strength ◽  
Statistical Evaluation ◽  
Laser Wavelength ◽  
Pinus Silvestris ◽  
Glue Joint ◽  
Weak Boundary ◽  
Different Types ◽  
Wood Surfaces

Summary The effect on glue joint strength of removing the layer of cells on end-grain surfaces of wood damaged by machining—the mechanical weak boundary layer (MWBL)—is presented. The wood surfaces have been laser ablated using different types of lasers of different wavelengths. The goal has been to determine whether or not the strength of end-grain glue joints is influenced by the MWBL and to show how the laser wavelength affects the glue joint strength. All tests were carried out with a PVAc-glue with hardener, and two different glue pressures were used. The joints were tested by bending notched and fatigued specimens. The statistical evaluation of the results shows that one laser gave a significantly higher glue joint strength than the others. One main conclusion is that the glue joint strength could have been improved with a stronger glue. An ESEM-analysis showed that fracture occurred primarily in the glueline and not in the boundary layer.

scholarly journals The Effect of Laser Wavelength on the Selective Vaporization of Cu-Zn Alloy in Laser Ablation at Low Pressure

2004 ◽  
Vol 44 (1) ◽  
pp. 220-222 ◽  
Author(s):  
Hideyuki Matsuta ◽  
Tariq Mahmood Naeem ◽  
Kazuaki Wagatsuma
Keyword(s):  
Laser Ablation ◽  
Low Pressure ◽  
Laser Wavelength ◽  
Zn Alloy

Comparative Study of Bismuth Composites Obtained via Pulsed Laser Ablation in a Liquid and in Air for Photocatalytic Application

2020 ◽  
Vol 312 ◽  
pp. 172-178
Author(s):  
Valery A. Svetlichnyi ◽  
Elena D. Fakhrutdinova ◽  
Tatiana S. Nazarova ◽  
Sergei A. Kulinich ◽  
Olga V. Vodyankina
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Photocatalytic Application ◽  
Vis Spectroscopy ◽  
Metallic Bismuth ◽  
Synthesized Materials

In the present work, bismuth-based nanoparticles of various compositions were obtained by pulsed laser ablation of a metallic bismuth target in water and air using a Q-switch Nd:YAG laser (wavelength of 1064 nm, pulse duration of 7 ns, frequency of 20 Hz, and pulse energy of 160 mJ). Then the samples were annealed in air at temperatures up to 600°C. A comparative analysis of the obtained powders was carried out using methods of X-ray diffraction, transmission electron microscopy, specific surface area measurements, IR-Fourier and UV-Vis Spectroscopy. The photocatalytic activity of the synthesized materials in the process of Rhodamine B decomposition under irradiation of a LED source (375 nm) was also studied.

Laser Ablation of Pzt Films for use in Bimorph Actuator Structures

1992 ◽  
Vol 285 ◽  
Author(s):  
Johannes Frantti ◽  
H. Moilanen ◽  
S. Leppävuori ◽  
A. Uusimäki
Keyword(s):  
Laser Ablation ◽  
Excimer Laser ◽  
Nd:Yag Laser ◽  
Low Voltage ◽  
Michelson Interferometer ◽  
Laser Wavelength ◽  
Silicon Substrates ◽  
Driving Voltage ◽  
Raman Spectrometry ◽  
Pzt Films

ABSTRACTLaser ablation has been used to produce piezoelectric films for use in a low voltage cantilever bimorph actuator structure. Nd doped lead zirconium titanate (PZT) films were deposited by a pulsed Q-switched Nd:YAG laser (wavelength 1064 nm) on to unheated silver-coated oxidised silicon substrates at a distance of 30 mm between substrate and target. Growth rates were typically 20 Å/s. The as-deposited PZT films were amorphous but contained small microcrystalline pyrochlore and perovskite regions. Optimisation of the annealing conditions resulted in perovskite as the main phase (T=750°C, t=2 h). A special fabrication technique (PbO covered PZT) was used to minimise film defects mainly caused by large particles.In order to improve the density of the film and deposition rates of the ablated PZT film, ablations using an XeCl excimer laser (wavelength 308 nm) under the influence of a static magnetic field were also studied. The decreased particle size in the deposited films showed that the surface quality of the films fabricated by the excimer laser was better than that of films deposited by the Nd:YAG laser. Films were studied using EDS, XRD and also micro-Raman spectrometry.Bimorph cantilever element structures were realised using Nd:YAG laser ablation. DC bending characteristics of these low voltage cantilever bimorphs were measured as a function of voltage using a Michelson interferometer. Displacements in the order of microns were obtained from a 15 mm x 4 mm x 80 �ement with a driving voltage level of 10 V.

scholarly journals Laser Ablation Studies of Deposited Silver Colloids Active in SERS

2002 ◽  
Vol 20 (1) ◽  
pp. 23-32 ◽  
Author(s):  
R. Torres La Porte ◽  
D. Silva Moreno ◽  
M. Castillejo Striano ◽  
M. Martiín Munñoz ◽  
J. V. García-Ramos ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Temporal Resolution ◽  
Mass Spectroscopy ◽  
Mass Spectra ◽  
Time Of Flight ◽  
Laser Wavelength ◽  
Ablation Plume ◽  
Expansion Velocity ◽  
Silver Colloids ◽  
532 Nm

Laser ablation of deposited silver colloids, active in SERS, is carried out at three different laser wavelengths (KrF, XeCl and Nd:YAG at λ = 248, 308 and 532 nm respectively). Emission form excited neutral Ag and Na atoms, present in the ablation plume, is detected with spectral and temporal resolution. The expansion velocity of Ag in the plume is estimated in ~1×104m s−1. Low-fluence laser ablation of the colloids yields ionized species that are analyzed by time-of-flight mass spectroscopy. Na+ and Agn+(n≤3) are observed. Composition of the mass spectra and widths of the mass peaks are found to be dependent on laser wavelength, suggesting that the dominant ablation mechanisms are different at the different wavelenghts.

scholarly journals Laser wavelength modulated pulsed laser ablation for selective and efficient production of graphene quantum dots

RSC Advances ◽  
2019 ◽  
Vol 9 (24) ◽  
pp. 13658-13663 ◽  
Author(s):  
Sukhyun Kang ◽  
Jeong Ho Ryu ◽  
Byoungsoo Lee ◽  
Kyung Hwan Jung ◽  
Kwang Bo Shim ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laser Ablation ◽  
Biomedical Applications ◽  
Graphene Quantum Dots ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Wavelength ◽  
Efficient Production ◽  
Laser Ablation In Liquid ◽  
Graphene Oxide Quantum Dots

Graphene quantum dots (GQDs) and graphene oxide quantum dots (GOQDs) can be selectively produced by wavelength-modulated pulsed laser ablation in liquid (PLAL) method, which can used in different applications such as optoelectronic and biomedical applications, respectively.

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