Mesoscopic Model for The Laser-Target Interaction

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Mendes Ribeiro ◽  
Marta M.D. Ramos ◽  
A.M. Stoneham

AbstractWe have developed a mesoscopic model for the study of pulsed laser ablation of transparent granular ceramics. The model enables the understanding of several features that happen at the surface of a transparent target and which play an important role in the evolution of the evaporation process.The results show that electron emission happens early, much before atom evaporation. High defect concentration regions (including grain boundaries, surface) are crucial for energy absorption. The model also predicts the generation of high intensity electric fields in places with high defect concentration, such as grain boundaries. Low fluences should have selective species removal, but higher fluences should give congruent removal.The dependence of the density of generated electrons, the evaporated species and energy on the material properties is included.

2012 ◽  
Vol 500 ◽  
pp. 351-356 ◽  
Author(s):  
Zeng Qiang Li ◽  
Jun Wang ◽  
Qi Wu

The mechanism of ultrashort pulsed laser ablation of polycrystalline diamond (PCD) is investigated using molecular dynamics simulation. The simulation model provides a detailed atomic-level description of the laser energy deposition to PCD specimens and is verified by an experiment using 300 fs laser irradiation of a PCD sample. It is found that grain boundaries play an important role in the laser ablation. Melting starts from the grain boundaries since the atoms in these regions have higher potential energy and are melted more easily than the perfect diamond. Non-homogeneous melting then takes place at these places, and the inner crystal grains melt more easily in liquid surroundings presented by the melting grain boundaries. Moreover, the interplay of the two processes, photomechanical spallation and evaporation, are found to account for material removal in ultrashort pulsed laser ablation of PCD.


CrystEngComm ◽  
2014 ◽  
Vol 16 (8) ◽  
pp. 1532-1539 ◽  
Author(s):  
Bo-Cheng Lin ◽  
Chang-Ning Huang ◽  
Pouyan Shen ◽  
Shuei-Yuan Chen

1989 ◽  
Vol 169 ◽  
Author(s):  
M. Grant Norton ◽  
Lisa A. Tietz ◽  
C. Barry Carter ◽  
Stephen E Russek ◽  
Brian H. Moeckly ◽  
...  

AbstractGrain boundaries in YBa2Cu3O7-δ thin films deposited on (001)-MgO by pulsed laser ablation have been characterized using selected area diffraction. In addition to twin boundaries, the presence of both low-angle and high-angle grain boundaries were characteristic of the film's microstructure. The presence of certain grain boundaries may be responsible for the weak-link Josephson behavior observed in small constrictions formed in superconducting films on MgO.


1998 ◽  
Vol 67 (5) ◽  
pp. 557-561 ◽  
Author(s):  
R.C. Issac ◽  
G.K. Varier ◽  
P. Gopinath ◽  
S.S. Harilal ◽  
V.P.N. Nampoori ◽  
...  

2003 ◽  
Author(s):  
Makoto Murai ◽  
Tomokazu Sano ◽  
Etsuji Ohmura ◽  
Isamu Miyamoto

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