TiN formation on Ti target by laser ablation method under different N2 gas pressure and laser scanning cycles: A wettability study

2021 ◽  
Vol 27 ◽  
pp. 101509
Author(s):  
Ensiye shabanlou ◽  
Babak Jaleh ◽  
Behnaz Feizi Mohazzab ◽  
Omidreza Kakuee ◽  
Reza Golbedaghi ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Scanning ◽  
Gas Pressure ◽  
Laser Ablation Method

scholarly journals Heat impact during laser ablation extraction of mineralised tissue micropillars

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samuel McPhee ◽  
Alexander Groetsch ◽  
Jonathan D. Shephard ◽  
Uwe Wolfram
Keyword(s):  
Laser Ablation ◽  
Mechanical Testing ◽  
Laser Scanning ◽  
Pulsed Laser ◽  
Temperature Response ◽  
Collagen Fibre ◽  
Pulsed Laser Ablation ◽  
Collagen Molecules ◽  
Ultrashort Pulsed Laser ◽  
The Impact

AbstractThe underlying constraint of ultrashort pulsed laser ablation in both the clinical and micromachining setting is the uncertainty regarding the impact on the composition of material surrounding the ablated region. A heat model representing the laser-tissue interaction was implemented into a finite element suite to assess the cumulative temperature response of bone during ultrashort pulsed laser ablation. As an example, we focus on the extraction of mineralised collagen fibre micropillars. Laser induced heating can cause denaturation of the collagen, resulting in ultrastructural loss which could affect mechanical testing results. Laser parameters were taken from a used micropillar extraction protocol. The laser scanning pattern consisted of 4085 pulses, with a final radial pass being 22 $$\upmu {\text {m}}$$ μ m away from the micropillar. The micropillar temperature was elevated to 70.58 $$^{\circ }{\text {C}}$$ ∘ C , remaining 79.42 $$^{\circ }{\text {C}}$$ ∘ C lower than that of which we interpret as an onset for denaturation. We verified the results by means of Raman microscopy and Energy Dispersive X-ray Microanalysis and found the laser-material interaction had no effect on the collagen molecules or mineral nanocrystals that constitute the micropillars. We, thus, show that ultrashort pulsed laser ablation is a safe and viable tool to fabricate bone specimens for mechanical testing at the micro- and nanoscale and we provide a computational model to efficiently assess this.

Effect of Non-equilibrium Pulsed Ejection of Si Species into Background Gas on the Formation of Si Nanocrystallite and Nanocrystal-film

2011 ◽  
Vol 1305 ◽  
Author(s):  
Ikurou Umezu ◽  
Shunto Okubo ◽  
Akira Sugimura
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Hydrogen Gas ◽  
Gas Pressure ◽  
Spatial Confinement ◽  
The Individual ◽  
Background Gas ◽  
Non Equilibrium

ABSTRACTThe Si nanocrystal-films are prepared by pulsed laser ablation of Si target in a mixture of helium and hydrogen gas. The total gas pressure and hydrogen partial gas pressure were varied to control structure of nanocrystal-film. The surface of Si nanocrystallite was hydrogenated and degree of hydrogenation increased with increasing hydrogen partial gas pressure. The aggregate structure of nanocrystal-film depended on both the total gas pressure and the hydrogen partial gas pressure. The former and the latter alter spatial confinement of Si species during deposition and the surface hydrogenation of individual nanocrystal, respectively. Spatial confinement increases probability of collision between nanocrystals in the plume. While, surface hydrogenation prevents coalescence of nanocrystals. The individual or aggregated nanocrystals formed in the plume reach the substrate and the nanocrystal-film is deposited on the substrate. The non-equilibrium growth processes during pulsed laser ablation are essential for the formation of the surface structure and the subsequent nanocrystal-film growth. Our results indicate that the structure of nanocrystal-film depends on the probabilities of collision and coalescence between nanocrystals in the plume. These probabilities can be varied by controlling the total gas pressure and the hydrogen partial gas pressure.

The Research Possibility of Definition Mass Biological Nanoobjects Using Terahertz Laser Ablation Method

2009 ◽  
Vol 4 (3) ◽  
pp. 74-77
Author(s):  
Mikhail Vagin ◽  
Anton Unitsyn ◽  
Aleksandr Petrov ◽  
Aleksandr Kozlov ◽  
Sergey Malyshkin ◽  
...  
Keyword(s):  
Particle Size ◽  
Laser Ablation ◽  
Molecular Mass ◽  
Aerosol Particle ◽  
Free Electron ◽  
Free Electron Laser ◽  
Thz Radiation ◽  
Laser Ablation Method ◽  
Aerosol Particle Size ◽  
Mass Definition

Possibility of mass definition using terahertz laser ablation method for biological nanoobjects is researched. Diffusion spectrometer of aerosols was applied for measuring the size of dispersed products of terahertz laser ablation. Dependence of molecular mass from the aerosol particle size was obtained for fragments of DNA λ-hind. This work was carried out using THz radiation of free electron laser of Siberian center of photochemical researches.

scholarly journals Fabrication, N-doping Mechanism and Evaluation of N-doped TiO2 Thin Films Based on Laser Ablation Method

2009 ◽  
Vol 2 (1) ◽  
pp. 17-23 ◽  
Author(s):  
S. Somekawa ◽  
Y. Kusumoto ◽  
H. Yang ◽  
M. Abdulla-Al-Mamun ◽  
B. Ahmmad
Keyword(s):  
Crystal Structure ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Laser Ablation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Laser Ablation Method ◽  
Dye Decomposition ◽  
N Doping ◽  
Keywords Laser

The relation among the change of the crystal structure, the amount of doped N and the photocatalytic activity for the decomposition of methylene blue was studied. The N-doping was promoted by the change of the crystal structure from the rutile phase to the anatase phase. The photocatalytic activity for the decomposition of methylene blue was enhanced by an increase in the amount of anatase crystals and doped N. Keywords: Laser ablation; N-doping process; Crystal change; N-doped TiO2 thin film; Dye decomposition. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2992        J. Sci. Res. 2 (1), 17-23 (2010) 

Influence of Laser Irradiation and Ambient Gas in Preparation of PZT Films by Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
Akiharu Morimoto ◽  
Shigeru Otsubo ◽  
Tatsuo Shimizu ◽  
Toshiharu Minamikawa ◽  
Yasuto Yonezawa ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Irradiation ◽  
Perovskite Structure ◽  
Film Surface ◽  
Target Material ◽  
Laser Ablation Method ◽  
Wide Range ◽  
Pzt Films ◽  
Ambient Gas ◽  
Substrate Temperatures

ABSTRACTPb(Zr0.52Ti0. 48)O3 (PZT) films were prepared on r-plane sapphire substrates by the laser ablation method utilizing ArF excimer laser in O2 or N2O environment. The composition of the films deposited in O2 environment was found to be fairly close to the composition of the target material for a wide range of substrate temperatures, 400 – 750 °c. Increasing the laser fluence (the laser power density) for the ablation enhances the formation of the perovskite structure rather than the pyrochlore one. Use of N2O ambient gas instead of O2 gas enhances the formation of the perovskite structure of PZT films. Furthermore, it was found that a laser irradiation on the growing film surface during deposition enhances the formation of the perovskite structure.

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