scholarly journals In-Situ and Ex-Situ Characterization of Femtosecond Laser-Induced Ablation on As2S3 Chalcogenide Glasses and Advanced Grating Structures Fabrication

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 72 ◽  
Author(s):  
Hongyang Wang ◽  
Dongfeng Qi ◽  
Xiaohan Yu ◽  
Yawen Zhang ◽  
Zifeng Zhang ◽  
...  
Keyword(s):  
Melting Point ◽  
Femtosecond Laser ◽  
Laser Fluence ◽  
Chalcogenide Glasses ◽  
Heating Temperature ◽  
Ex Situ ◽  
Direct Writing ◽  
Melting Pool ◽  
Writing Technology

Femtosecond laser pulse of 800 nm wavelength and 150 fs temporal width ablation of As2S3 chalcogenide glasses is investigated by pump-probing technology. At lower laser fluence (8.26 mJ/cm2), the surface temperature dropping to the melting point is fast (about 43 ps), which results in a clean hole on the surface. As the laser fluence increases, it takes a longer time for lattice temperature to cool to the melting point at high fluence (about 200 ps for 18.58 mJ/cm2, about 400 ps for 30.98 mJ/cm2). The longer time of the surface heating temperature induces the melting pool in the center, and accelerates material diffusing and gathering surrounding the crater, resulting in the peripheral rim structure and droplet-like structure around the rim. In addition, the fabricated long periodic As2S3 glasses diffraction gratings can preserve with high diffraction efficiency by laser direct writing technology.

scholarly journals In-situ monitoring and ex-situ elasticity mapping of laser induced metal melting pool using ultrasound: Numerical and experimental approaches

2021 ◽  
Vol 71 ◽  
pp. 178-186
Author(s):  
Teng Yang ◽  
Yuqi Jin ◽  
Brian Squires ◽  
Tae-Youl Choi ◽  
Narendra B. Dahotre ◽  
...  
Keyword(s):  
In Situ Monitoring ◽  
Ex Situ ◽  
Melting Pool ◽  
Experimental Approaches ◽  
Metal Melting

High-Resolution In Situ Patterning of Perovskite Quantum Dots via Femtosecond Laser Direct Writing

Nanoscale ◽  
2021 ◽  
Author(s):  
Shuyu Liang ◽  
Yue-Feng Liu ◽  
Shenyuan Wang ◽  
Hong Xia ◽  
Hong-Bo Sun
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
Femtosecond Laser ◽  
Information Storage ◽  
Colloidal Quantum Dots ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Perovskite Quantum Dots ◽  
Patterning Technique

Colloidal quantum dots (QDs) have exhibited great potentials for optoelectronic applications, including display, laser, anti-counterfeiting and information storage. However, high-resolution patterning technique of QDs is still a challenge, while precise...

Experimental Measurements of Spectral Emissivity of Al-Si Coated Steel Blanks Undergoing Rapid Heating

2014 ◽  
Author(s):  
N. L. Chester ◽  
M. A. Wells ◽  
K. J. Daun
Keyword(s):  
Heating Temperature ◽  
Rapid Heating ◽  
Spectral Emissivity ◽  
Ex Situ ◽  
Temperature History ◽  
Detailed Knowledge ◽  
Coated Steel ◽  
Heating Rates ◽  
Rapid Changes

Detailed knowledge of the blank temperature history is essential in hot forming die quenching, in order to ensure adequate austenitization of the steel and transformation of a protective Al-Si later into a permanent Al-Si-Fe coating. This, in turn, requires detailed knowledge of the blank emissivity, which is complicated by the fact that the coating undergoes rapid changes in surface chemistry, and surface roughness as it is heated. This paper spectral emissivity of Usibor® 1500 P as it undergoes heating. Samples were heated in a DSI Gleeble® 3500 under prescribed heating rates. The spectral emissivity was measured ex situ using an FTIR reflectometer, and in situ with a NIR-spectrometer. While the trends agree with manufacturer data in the cases of the as-received and final furnace heating temperature of 900°C, the spectral emissivity changes at a faster rate than previously reported.

Three-dimensional micropatterning of graphene by femtosecond laser direct writing technology

2019 ◽  
Vol 45 (1) ◽  
pp. 113 ◽  
Author(s):  
Yu-Qing Liu ◽  
Jiang-Wei Mao ◽  
Zhao-Di Chen ◽  
Dong-Dong Han ◽  
Zhi-Zhen Jiao ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Three Dimensional ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Writing Technology

Femtosecond laser direct writing bio-gel template for in situ synthesis of nanoparticles

2014 ◽  
Vol 7 (4) ◽  
pp. 608-615
Author(s):  
刘东旭 LIU Dong-xu ◽  
夏虹 XIA Hong ◽  
孙允陆 SUN Yun-lu ◽  
陈岐岱 CHEN Qi-dai ◽  
董文飞 DONG Wen-fei
Keyword(s):  
Femtosecond Laser ◽  
In Situ Synthesis ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Synthesis Of Nanoparticles

scholarly journals In situ and ex-situ physical scenario of the femtosecond laser-induced periodic surface structures

2019 ◽  
Vol 27 (7) ◽  
pp. 10087 ◽  
Author(s):  
Xiaohan Yu ◽  
Dongfeng Qi ◽  
Hongyang Wang ◽  
Yawen Zhang ◽  
Letian Wang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Surface Structures ◽  
Ex Situ ◽  
Periodic Surface

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

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