A previously developed one-dimensional (ID) computational model for heat flow and nonequilibrium phase change phenomena induced by pulsed-laser irradiation has been extended to two-dimensions. The 2D modeling focuses attention on the heat flow from localized sources embedded in an otherwise planar matrix. For example, nucleation events occurring in undercooled liquids such as molten Si formed by pulsed-laser melting of amorphous Si (a-Si) and inhomogeneous absorption due to randomly occurring defects in targets used for pulsed-laser ablation can be treated. Concepts introduced in the ID modeling, such as the state diagram and the state array are extended to 2D and refined. ...
continued below
Publisher Info:
Oak Ridge National Lab., TN (United States)
Place of Publication:
Tennessee
Provided By
UNT Libraries Government Documents Department
Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.
Descriptive information to help identify this article.
Follow the links below to find similar items on the Digital Library.
Description
A previously developed one-dimensional (ID) computational model for heat flow and nonequilibrium phase change phenomena induced by pulsed-laser irradiation has been extended to two-dimensions. The 2D modeling focuses attention on the heat flow from localized sources embedded in an otherwise planar matrix. For example, nucleation events occurring in undercooled liquids such as molten Si formed by pulsed-laser melting of amorphous Si (a-Si) and inhomogeneous absorption due to randomly occurring defects in targets used for pulsed-laser ablation can be treated. Concepts introduced in the ID modeling, such as the state diagram and the state array are extended to 2D and refined. As an example of the calculations that are now possible, the laser-induced formation and propagation of buried liquid layers are followed in two dimensions for the case of a-Si on a crystalline silicon substrate. It is demonstrated how solid phase growth from individual nucleation sites gives rise to a nearly planar liquid layer propagating through the a-Si. Another example briefly addresses questions related to the early stages of the laser ablation of insulators such as MgO, where it is believed that the absorption of the laser radiation occurs at localized but extended regions of high concentrations of defects. The 2-D program has been rewritten for massively parallel machines such as the Intel Paragons in ORNL`s Center for Computational Sciences by one of us (CLL), thus allowing larger and more accurate calculations for complex systems to be carried out in reasonable times.
This article is part of the following collection of related materials.
Office of Scientific & Technical Information Technical Reports
Reports, articles and other documents harvested from the Office of Scientific and Technical Information.
Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Liu, C. L. & Wood, R. F.Modeling and simulation of pulsed laser annealing and ablation of solid materials,
article,
April 1995;
Tennessee.
(digital.library.unt.edu/ark:/67531/metadc703855/:
accessed April 22, 2018),
University of North Texas Libraries, Digital Library, digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.