Precise nanosecond time resolved infrared radiometry measurements of laser induced silicon phase change and melting front propagation

2008 ◽  
Vol 103 (8) ◽  
pp. 084909 ◽  
Author(s):  
J. Martan ◽  
N. Semmar ◽  
O. Cibulka
2018 ◽  
Vol 22 (6 Part B) ◽  
pp. 2723-2732
Author(s):  
Josef Stetina ◽  
Tomas Mauder ◽  
Lubomir Klimes ◽  
Pavel Charvat

Author(s):  
Dominic Groulx ◽  
Wilson Ogoh

One way of storing thermal energy is through the use of latent heat energy storage systems. One such system, composed of a cylindrical container filled with paraffin wax, through which a copper pipe carrying hot water is inserted, is presented in this paper. It is shown that the physical processes encountered in the flow of water, the heat transfer by conduction and convection, and the phase change behavior of the phase change material can be modeled numerically using the finite element method. Only charging (melting) is treated in this paper. The appearance and the behavior of the melting front can be simulated by modifying the specific heat of the PCM to account for the increased amount of energy, in the form of latent heat of fusion, needed to melt the PCM over its melting temperature range. The effects of adding fins to the system are also studied, as well as the effects of the water inlet velocity.


1994 ◽  
Vol 343 ◽  
Author(s):  
M. Libera

ABSTRACTThe bit-erase process in phase-change optical storage is based on the amorphous to crystalline transformation. While there has been significant progress developing compositions and multilayered media for phase-change applications, quantitative studies of the crystallization kinetics and microstructural development are generally lacking. This paper describes work quantifying crystallization in GeTe thin films. Microstructural changes during isothermal annealing are measured using in-situ hot-stage optical microscopy. This technique measures the fraction crystallized, the number of crystallites, and crystallite radii as a function of time. These data are sufficient to deconvolute the individual contributions of nucleation and growth. We find an Avrami exponent of ∼4, consistent with time-resolved reflection/transmission studies. This exponent is due to 2-D growth at a constant rate plus transient nucleation. The data are used in a kinetic model to simulate non-isothermal crystallization during focused-laser heating characteristic of the bit-erase process.


1993 ◽  
Author(s):  
Jane W. Maclachlan Spicer ◽  
W. D. Kerns ◽  
Leonard C. Aamodt ◽  
Robert Osiander ◽  
John C. Murphy

2008 ◽  
Vol 1072 ◽  
Author(s):  
Yuan Zhang ◽  
Simone Raoux ◽  
Daniel Krebs ◽  
Leslie E. Krupp ◽  
Teya Topuria ◽  
...  

ABSTRACTPhase change nanodot arrays were fabricated using self-assembly diblock copolymer template PS-b-PMMA (polystyrene-poly (methyl-methacrylate)) and studied by time resolved X-ray diffraction. The size of the nanodots was less than 15nm in diameter with 40nm spacing. This method is quite flexible regarding the patterned materials, and can be used on different substrates. The crystallization behavior of small scale phase change nanodot arrays was studied for different materials, such as Ge15Sb85, Ge2Sb2Te5 and Ag and In doped Sb2Te. It was found that the nanodots had higher crystallization temperatures compared to their corresponding blanket films and crystallized over a broader temperature range.


1998 ◽  
Vol 37 (8) ◽  
pp. 680-692 ◽  
Author(s):  
Robert Osiander ◽  
Jane W.M. Spicer

Sign in / Sign up

Export Citation Format

Share Document