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.

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.

Size classification of Si nanoparticles formed by pulsed laser ablation in helium background gas

1999 ◽  
Vol 69 (S1) ◽  
pp. S243-S247 ◽  
Author(s):  
T. Makino ◽  
N. Suzuki ◽  
Y. Yamada ◽  
T. Yoshida ◽  
T. Seto ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Size Classification ◽  
Si Nanoparticles ◽  
Background Gas

scholarly journals Highly-repeatable generation of very small nanoparticles by pulsed-laser ablation in liquids of a high-speed rotating target

2016 ◽  
Vol 18 (48) ◽  
pp. 32868-32875 ◽  
Author(s):  
A. Resano-Garcia ◽  
S. Champmartin ◽  
Y. Battie ◽  
A. Koch ◽  
A. En Naciri ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Ag Nanoparticles ◽  
High Speed ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Ablation In Liquids ◽  
Silver Target ◽  
Rotating Target ◽  
Small Nanoparticles

Very small and pure Ag nanoparticles are generated by pulsed-laser ablation in water of a silver target rotated at a high-speed.

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

Non-equilibrium Growth Processes of Porous TiO2 Nanocrystal-films during Pulsed Laser Ablation

2013 ◽  
Vol 1497 ◽  
Author(s):  
Ikurou Umezu ◽  
Nobuyasu Yagi ◽  
Akira Sugimura ◽  
Takehito Yoshida
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Hierarchical Structures ◽  
Pulsed Laser Ablation ◽  
Rutile Phase ◽  
Gas Pressure ◽  
Target Distance ◽  
Structural Formation ◽  
Background Gas ◽  
Non Equilibrium

ABSTRACTWe performed pulsed laser ablation of titanium dioxide (TiO2) target in O2 background gas. Effects of background gas pressure and substrate target distance on the structure of deposited films are clarified. The hierarchical structures are observed when we change scale of observation. The film deposited on the substrate is composed of primary nanocrystal and secondary porous-aggregated-nanostructures. The primary nanocrystal changes from anatase to rutile phase with increasing background gas pressure or substrate target distance. The porosity of secondary aggregated structure increases with increasing background gas pressure or substrate target distance. The similarity between the effects of background gas and substrate target distance indicates that confinement of the plume between target and substrate is important for structural formation. The non-equilibrium aggregation processes of nanocrystals in the plume and on the substrate are essential for the hierarchical structure of the nanocrystal film.

Characterization of BaTiO3 Thin Films Deposited by Pulsed-Laser Ablation

1990 ◽  
Vol 201 ◽  
Author(s):  
Christopher Scarfone ◽  
M. Grant Norton ◽  
C. Barry Carter ◽  
Jian Li ◽  
James W. Mayer
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Film Surface ◽  
Pulsed Laser Ablation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Channeling ◽  
Very High

AbstractThin films of barium titanate (BaTiOs) have been deposited by pulsed-laser ablation onto (001)-oriented MgO substrates. The films were epitactic as evidenced by both x-ray diffraction and ion-channeling techniques. The film surface appeared smooth and contained a low density of particulates. This latter feature is believed to be due to the formation of target pellets having a very high density.

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.

Annealing effects on structures and optical properties of silicon nanostructured films prepared by pulsed-laser ablation in inert background gas

2001 ◽  
Vol 90 (10) ◽  
pp. 5075-5080 ◽  
Author(s):  
Toshiharu Makino ◽  
Yuka Yamada ◽  
Nobuyasu Suzuki ◽  
Takehito Yoshida ◽  
Seinosuke Onari
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Nanostructured Films ◽  
Annealing Effects ◽  
Background Gas
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