scholarly journals Reactive pulsed laser ablation: Plasma studies

2006 ◽  
Vol 24 (2) ◽  
pp. 311-320 ◽  
Author(s):  
RAJ K. THAREJA ◽  
A.K. SHARMA
Keyword(s):  
Laser Ablation ◽  
Energy Levels ◽  
Pulsed Laser ◽  
Optical Emission ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
Taylor Instability ◽  
Degree Of Polarization ◽  
Optical Emission Spectrum ◽  
Rayleigh Taylor Instability

We report on the pulsed laser ablation of aluminum (Al) plasma in presence of ambient nitrogen to understand the formation of aluminum nitride (AlN). Formation of carbon nitride (CN) and titanium oxide (TiO) by pulsed laser-ablation of graphite and titanium targets in presence of ambient nitrogen and oxygen is also compared. We discuss the dynamics of plasma expansion based on existing models, shock and drag models, and the plasma gas interface distortion, Rayleigh-Taylor instability at various ambient pressures of nitrogen. Since Rayleigh-Taylor instability may give rise to self-generated magnetic field in the plasma, an attempt is made to understand the mechanism of generation as well as the estimation of this field near the focal spot using the information from the images of the expanding plasma. This is the first time images of the expanding plume are used to estimate self generated magnetic fields. At the irradiance level used in the experiment the field is high very close to the target surface therefore we expect splitting of the energy levels thus giving rise to emissions that may be anisotropic in nature. We discuss the extent of anisotropy by measuring the degree of polarization using emission intensity in optical emission spectrum of selected Al III transition 4s2S1/2–4p2P3/2oat 569.6 nm using both nanosecond and picosecond pulses.

Effect of the dynamic absorptance of a metallic target surface on pulsed laser ablation

2006 ◽  
Vol 203 (5) ◽  
pp. 906-918 ◽  
Author(s):  
Li Li ◽  
Duanming Zhang ◽  
Zhihua Li ◽  
Li Guan ◽  
Xinyu Tan ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
Metallic Target

Does the Subsurface Superheating Effect Really Exist?

1998 ◽  
Vol 526 ◽  
Author(s):  
Valentin Craciun ◽  
Doina Craciun
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Target Material ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
Laser Wavelength ◽  
Gas Release ◽  
Actual Mechanism ◽  
Emission Volume ◽  
Modification Of The Surface

AbstractThe existence inside targets during pulsed laser ablation of a sub-surface superheating effect (SSSH) has been predicted by numerical temperature estimations. The experimental evidence has been so far only indirect, based on the modification of the surface morphology caused by the explosive volume boiling induced by the SSSH effect. However, round-shaped micrometer-sized cavities formed by gas release due to volume boiling have been found on several target materials even when the temperature estimations did not predict any SSSH effect. Although the SSSH effect could exist under certain conditions, it seems that it is not a prerequisite for explosive volume boiling which is the actual mechanism responsible for droplets emission. Volume boiling could occur whenever a thick liquid layer, whose temperature is much higher than the equilibrium boiling value is formed and lasts for several tens of nanoseconds on the target surface, a situation usually found when the laser wavelength is poorly absorbed by the target material.

Pulsed laser ablation-deposition of La0.5Sr0.5CoO3 for use as electrodes in nonvolatile ferroelectric memories

1996 ◽  
Vol 11 (6) ◽  
pp. 1514-1519 ◽  
Author(s):  
R. Dat ◽  
O. Auciello ◽  
D. J. Lichtenwalner ◽  
A. I. Kingon
Keyword(s):  
Laser Ablation ◽  
Emission Spectroscopy ◽  
Smooth Surface ◽  
Optical Emission Spectroscopy ◽  
Pulsed Laser ◽  
Optical Emission ◽  
Pulsed Laser Ablation ◽  
Deposition Parameters ◽  
Ferroelectric Memories ◽  
Oxygen Interaction

La0.5Sr0.5CoO3 (LSCO) thin films have been deposited on (100) MgO substrates using pulsed laser ablation-deposition (PLAD). The crystallographic orientation of LSCO was found to be dependent on the surface treatment of (100) MgO prior to deposition. PLAD deposition parameters were optimized to yield LSCO films with an RMS surface roughness of 40–50 Å. A smooth surface morphology was reproduced as long as the oxygen content of the LSCO target was preserved. Otherwise, “splashing” occurred which resulted in the transfer of condensed particles from molten spherical globules of LSCO from the target to the substrate. Splashing was subsequently eliminated and smooth surface quality was restored after annealing the LSCO target at 550 °C in oxygen for 3 h. Optical emission spectroscopy (OES) of the LSCO's plume identified excited atomic cobalt neutrals, excited singly ionized strontium and lanthanum, and excited molecular LaO species. Oxygen interaction with the plume produced no new species. Furthermore, the OES data suggest that the observed LaO molecules were not created by the chemical reaction between La and O2 during ablation, but were ejected directly from the target during the PLAD process.

scholarly journals Optical Diagnostics during Pulsed Laser Ablation in Liquid (PLAL) for the Production of Metallic Nanoparticles

2021 ◽  
Vol 11 (21) ◽  
pp. 10344
Author(s):  
Marcella Dell’Aglio ◽  
Alessandro De Giacomo
Keyword(s):  
Laser Ablation ◽  
Metallic Nanoparticles ◽  
Bubble Dynamics ◽  
Pulsed Laser ◽  
Optical Emission ◽  
Pulsed Laser Ablation ◽  
Laser Ablation In Liquid ◽  
Optical Techniques ◽  
New Material ◽  
Specific Stage

Pulsed laser ablation in liquid (PLAL) is gaining an important role as a methodology for producing nanostructures without the use of chemicals and stabilizers. Several nanomaterials have been produced and the engineering of PLAL is becoming an important task for the dissemination of this approach for nanostructure production. Monitoring the processes involved in the PLAL during nanostructure production can be extremely useful for improving the experimental methods and for pushing PLAL to new material formation. In this paper, we discuss the use of optical techniques for investigating the specific stages involved in the production of nanomaterials with PLAL. In particular, the recent advancements of these optical techniques for each specific stage of the PLAL process will be discussed: optical emission spectroscopy and imaging for the investigation of the plasma phase, shadowgraph imaging for the investigation of the cavitation bubble dynamics and different scattering techniques for the visualization of the produced nanostructure.

scholarly journals Role of confining liquids on the properties of Cu@Cu2O nanoparticles synthesized by pulsed laser ablation and a correlative ablation study of the target surface

RSC Advances ◽  
2019 ◽  
Vol 9 (26) ◽  
pp. 15124-15139 ◽  
Author(s):  
Prahlad K. Baruah ◽  
Ashwini K. Sharma ◽  
Alika Khare
Keyword(s):  
Laser Ablation ◽  
Organic Solvents ◽  
Pulsed Laser ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
Cu Nanoparticles ◽  
Cu2o Nanoparticles ◽  
Ablation Study

Formation of insufficiently oxidized Cu nanoparticles by laser ablation in organic solvents is correlated with the ablation of the target surface.

Temperature Dependent Up-Conversion Luminescence Properties of Er3+ Doped KNN Ultrafine Powders Prepared by Pulsed Laser Ablation in Liquid

2020 ◽  
Vol 998 ◽  
pp. 197-202
Author(s):  
Zhen Liu ◽  
Di Hu Chen
Keyword(s):  
Electron Microscopy ◽  
Laser Ablation ◽  
Emission Intensity ◽  
Energy Levels ◽  
Pulsed Laser ◽  
Green Emission ◽  
Pulsed Laser Ablation ◽  
Temperature Sensing ◽  
Ultrafine Powders ◽  
Temperature Dependent

Er3+ doped potassium sodium niobate (KNN: Er) ultrafine powders have been prepared by pulsed laser ablation in water. X-ray diffraction (XRD) pattern of the sample demonstrated that the as-synthesized powders were crystalized in orthorhombic phase. Scanning electron microscopy (SEM) and transmittance electron microscopy (TEM) images exhibited that the morphology of ultrafine powders are cube-like. Under the excitation of 980 nm laser, the sample exhibits green emission, which is originated from the transition of thermal coupled energy levels (2H11/2, 4S3/2) to ground state level 4I15/2. Temperature dependent up-conversion emission intensity associated with thermal quenching of total green emission band and the fluorescence intensity ratio (FIR) between two sub-emission bands related to population of thermal coupled energy levels are investigated for temperature sensing in the temperature range of 300 K to 480 K. The temperature sensing performances related to different technique were discussed. A maximum relative sensitivity reaches 1.01% K-1 at 464 K for emission intensity thermometry and that is 0.84% K-1 at 374 K for FIR thermometry technique. All these results show that KNN: Er ultrafine phosphors prepared via pulsed laser ablation in water have prospect for non-contact temperature sensing.

scholarly journals Nanoparticle Formation and Deposition by Pulsed Laser Ablation

2020 ◽  
Author(s):  
Toshio Takiya ◽  
Naoaki Fukuda
Keyword(s):  
Laser Ablation ◽  
High Speed ◽  
Pulsed Laser ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
History Of ◽  
Good Technique ◽  
Background Gas ◽  
High Temperature Vapor ◽  
Very High

Pulsed Laser Ablation (PLA) in background gas is a good technique to acquire specific nanoparticles under strong non-equilibrium states. Here, after a history of PLA is mentioned, the application of nanoparticles and its deposition films to the several fields will be described. On the target surface heated with PLA, a Knudsen layer is formed around the adjacent region of the surface, and high-pressure and high-temperature vapor atoms are generated. The plume formed by evaporated atoms blasts off with very high-speed and expands rapidly with a shock wave. A supercooling phenomenon occurs during this process, and number of nucleus of nanoparticle forms in vapor-phase. The nuclei grow by the condensation of vapor atoms and deposit on a substrate as nanoparticle film. If the radius of nanoparticle is uniformized, a self-ordering formation can be shown as a result of interactive process between each nanoparticle of the same size on the substrate. In this chapter, the related technology to realize a series of these processes will be expounded.

Optical emission accompanying pulsed laser ablation of graphite: experiment and kinetics

2004 ◽  
Author(s):  
F. Stokker-Cheregi ◽  
Carmen Ristoscu ◽  
V. Stancalie ◽  
Ion N. Mihailescu
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Optical Emission ◽  
Pulsed Laser Ablation

scholarly journals Imaging spectroscopy of Ag plasmas produced by infrared nanosecond laser ablation

2019 ◽  
Vol 34 (3) ◽  
pp. 489-497 ◽  
Author(s):  
J. J. Camacho ◽  
M. Oujja ◽  
M. Sanz ◽  
A. Martínez-Hernández ◽  
I. Lopez-Quintas ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Imaging Spectroscopy ◽  
Pulsed Laser ◽  
Optical Emission ◽  
Pulsed Laser Ablation ◽  
Nanosecond Laser ◽  
Nanosecond Laser Ablation

Spatially and temporally resolved optical emission spectroscopy has been used to study plasmas formed by 1064 nm pulsed laser ablation of silver targets in a vacuum.

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