Instabilities and Structure Formation in Laser Processing

1995 ◽  
Vol 397 ◽  
Author(s):  
D. Bàuerle ◽  
E. Arenholz ◽  
N. Arnold ◽  
J. Heitz ◽  
P.B. Kargl
Keyword(s):  
Chemical Vapor Deposition ◽  
Laser Ablation ◽  
Structure Formation ◽  
Coherent Structures ◽  
Vapor Deposition ◽  
Laser Processing ◽  
Chemical Vapor ◽  
Surface Modifications ◽  
Different Types

ABSTRACTThis paper gives an overview on different types of instabilities and structure formation in various fields of laser processing. Among the examples discussed in detail are non-coherent structures observed in laser-induced chemical vapor deposition (LCVD), in laser-induced surface modifications, and in laser ablation of polymers.

scholarly journals Facile Functionalization via Plasma-Enhanced Chemical Vapor Deposition for the Effective Filtration of Oily Aerosol

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1490 ◽  
Author(s):  
Sanghyun Roh ◽  
Sungmin Kim ◽  
Jooyoun Kim
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Filter Design ◽  
Chemical Vapor ◽  
Surface Modifications ◽  
Solid Particles ◽  
Oxygen Species ◽  
Plasma Process ◽  
Filter Performance ◽  
Filtration Performance

With the growing concern about the health impacts associated with airborne particles, there is a pressing need to design an effective filter device. The objective of this study is to investigate the effect of plasma-based surface modifications on static charges of electrospun filter media and their resulting filtration performance. Polystyrene (PS) electrospun web (ES) had inherent static charges of ~3.7 kV due to its electric field-driven process, displaying effective filtration performance. When oxygen species were created on the surface by the oxygen plasma process, static charges of electret media decreased, deteriorating the filter performance. When the web surface was fluorinated by the plasma-enhanced chemical vapor deposition (PECVD), the filtration efficiency against oily aerosol significantly increased due to the combined effect of decreased wettability and strong static charges (~−3.9 kV). Solid particles on the charged media formed dendrites as particles were attracted to other layers of particles, building up a pressure drop. The PECVD process is suggested as a facile functionalization method for effective filter design, particularly for capturing oily aerosol.

scholarly journals Welding, Joining, and Coating of Metallic Materials

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2640
Author(s):  
Michael Zinigrad ◽  
Konstantin Borodianskiy
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Metallic Substrate ◽  
Metallic Materials ◽  
Special Issue ◽  
Different Types ◽  
Recent Developments ◽  
Micro Arc Oxidation

Welding, joining, and coating of metallic materials are among the most applicable fabrication processes in modern metallurgy. Welding or joining is the manufacture of a metal one-body workpiece from several pieces. Coating is the process of production of metallic substrate with required properties of the surface. A long list of specific techniques is studied during schooling and applied in industry; several include resistant spot, laser or friction welding, micro arc oxidation (MAO), chemical vapor deposition (CVD), and physical vapor deposition (PVD), among others. This Special Issue presents 21 recent developments in the field of welding, joining, and coating of various metallic materials namely, Ti and Mg alloys, different types of steel, intermetallics, and shape memory alloys.

Control of diameter of ZnO nanorods grown by chemical vapor deposition with laser ablation of ZnO

2007 ◽  
Vol 42 (1-6) ◽  
pp. 409-414 ◽  
Author(s):  
Takashi Hirate ◽  
Takashi Kimpara ◽  
Shinichi Nakamura ◽  
Tomomasa Satoh
Keyword(s):  
Chemical Vapor Deposition ◽  
Laser Ablation ◽  
Vapor Deposition ◽  
Zno Nanorods ◽  
Chemical Vapor

Effects of Laser Ablation on Growth of ZnO/ZnS/ZnO Multilayer Structured Nanorods by Chemical Vapor Deposition

2008 ◽  
Vol 1144 ◽  
Author(s):  
Takashi Hirate ◽  
Hiroaki Koisikawa ◽  
Makoto Yugi ◽  
Takuya Kumada ◽  
Yuki Matsuzawa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Laser Ablation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Zno Nanorods ◽  
Chemical Vapor ◽  
The Other ◽  
The Third

ABSTRACTZnO is an attractive II-VI compound semiconductor material for various optoelectronic devices. Recently, growth of various nanostructures of ZnO such as nanorod, nanobelt, nanowall, etc. has been reported, and ZnO has been considered as a promising material for nanodevices. We have studied on fabrication of aligned ZnO nanorods by a low-pressure thermal chemical vapor deposition (CVD) method cooperated with laser ablation of Mn pellet. In this paper, we report on fabrication of ZnO/ZnS/ZnO multilayer structured nanorods and particularly on effects of laser ablation on the morphology of the nanorods intending to develop a new electroluminescent device including ZnO nanorods. The fabrication method of ZnO/ZnS/ZnO multilayer structured nanorods is almost same method used in our previous study. Metal Zn vapor and O2 gas or H2S are used as precursors to synthesize ZnO or ZnS, and N2 is used as carrier gas. A Mn pellet is placed near a Si(111) substrate in a deposition chamber and ablated by a pulsed Nd:YAG laser beam (wavelength =1.064 mm, pulse width = 8 ns, repetition frequency = 10 shots/sec). The pressure is 13.3 Pa and the temperature is 550 C. When ZnO is grown, O2 of 0.88 SCCM mass flow rate is used as a precursor. When ZnS is grown, on the other hand, H2S of 2.0 SCCM mass flow rate is used as a precursor. The growth time is 15 min for each layer. Firstly, ZnO nanorods are grown. Laser ablation of Mn is executed for initial 3 min and only CVD is performed for remaining 12 min. The vertically aligned ZnO nanorods with 100 nm diameter and 1500 nm height are grown. Secondly, ZnS nanorod is grown on the top surface of the first ZnO nanorods. In this process, the morphology is not so dependent on execution of laser ablation of Mn for initial 3 min in this growth process. Finally, ZnO layer is again grown on ZnS/ZnO nanorods described above. When the laser ablation of Mn for initial 3 min is not executed, many fine ZnO whiskers with long length are grown with random directions on the top surface and on the side surfaces of ZnS/ZnO nanorods. When the laser ablation of Mn for initial 3 min is executed, on the other side, a thick whisker is grown on top surface of ZnS/ZnO nanorods. The shape is not nanorod. The diameter is abruptly decreased and the tip is very sharp. The growth of ZnO whisker on the side surface of ZnS/ZnO nanorods is not almost observed. It is found that the laser ablation of Mn for initial 3 min in the third ZnO growth strongly influences the morphology of the third ZnO layer. We estimate that the Mn species that are ablated from a Mn pellet and reaches the surface of ZnS/ZnO nanorods change any quality of the surface of ZnS/ZnO nanorods. We are now studying of finding the growth conditions of the third ZnO layer with morphology of nanorod on ZnS/ZnO nanorods that is considered to be suitable for electroluminescent devices.

Growth of InSb/GaAs Layers on YIG-Coated GGG Substrate

1992 ◽  
Vol 281 ◽  
Author(s):  
C. Jelen ◽  
S. Charrière ◽  
M. Razeghi ◽  
V. J. Leppert
Keyword(s):  
Chemical Vapor Deposition ◽  
Laser Ablation ◽  
Liquid Phase ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metalorganic Chemical

ABSTRACTWe report the first growth of InSb and GaAs epilayers upon a garnet (YIG = Y3Fe5O12) epilayer. The YIG was deposited using liquid phase epitaxy on a garnet (GGG = Gd3Ga5O12) substrate oriented in the [111] direction. The growth of the GaAs was carried out using laser ablation and no superlattice was used to buffer the lattice mismatch between YIG and GaAs. The growth of InSb was done by low-pressure metalorganic chemical vapor deposition. From x-ray diffraction analysis it was found that the GaAs and InSb were both (110) monocrystalline epitaxial layers.

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