Thermocapillary convection in a model float-zone

1990 ◽  
Author(s):  
G. NEITZEL ◽  
J. HYER ◽  
D. JANKOWSKI
Keyword(s):  
Thermocapillary Convection ◽  
Float Zone

Energy stability of thermocapillary convection in a model of the float-zone crystal-growth process

1990 ◽  
Vol 217 ◽  
pp. 639-660 ◽  
Author(s):  
Y. Shen ◽  
G. P. Neitzel ◽  
D. F. Jankowski ◽  
H. D. Mittelmann
Keyword(s):  
Finite Length ◽  
Marangoni Number ◽  
Growth Process ◽  
Thermocapillary Convection ◽  
Energy Stability ◽  
Stability Criteria ◽  
Lagrange Equations ◽  
Float Zone ◽  
Crystal Growth Process ◽  
Axisymmetric Disturbances

Energy stability theory has been applied to a basic state of thermocapillary convection occurring in a cylindrical half-zone of finite length to determine conditions under which the flow will be stable. Because of the finite length of the zone, the basic state must be determined numerically. Instead of obtaining stability criteria by solving the related Euler–Lagrange equations, the variational problem is attacked directly by discretization of the integrals in the energy identity using finite differences. Results of the analysis are values of the Marangoni number, MaE, below which axisymmetric disturbances to the basic state will decay, for various values of the other parameters governing the problem.

Stability of Thermocapillary Convection in Float-Zone Crystal Growth

1991 ◽  
pp. 45-56 ◽  
Author(s):  
Hans D. Mittelmann ◽  
Cindy C. Law ◽  
Daniel F. Jankowski ◽  
G. Paul Neitzel
Keyword(s):  
Crystal Growth ◽  
Thermocapillary Convection ◽  
Float Zone

Instability of thermocapillary–buoyancy convection in shallow layers. Part 2. Suppression of hydrothermal waves

1998 ◽  
Vol 359 ◽  
pp. 165-180 ◽  
Author(s):  
S. BENZ ◽  
P. HINTZ ◽  
R. J. RILEY ◽  
G. P. NEITZEL
Keyword(s):  
Free Surface ◽  
Crystal Growth ◽  
Growth Process ◽  
Thermocapillary Convection ◽  
Model System ◽  
Wave Instability ◽  
Float Zone ◽  
Crystal Growth Process ◽  
Hydrothermal Wave ◽  
Buoyancy Convection

Hydrothermal-wave instabilities in thermocapillary convection are known to produce undesirable effects when they occur during the float-zone crystal-growth process, and perhaps in other situations. Suppression of the hydrothermal-wave instability produced in the model system of Part 1 (Riley & Neitzel 1998) is demonstrated through the sensing of free-surface temperature perturbations and the periodic addition of heat at the free surface along lines parallel to the crests of the hydrothermal waves.

A Numerical Study of Effect of Liquid Encapsulation on Thermocapillary Convection in Liquid Bridge

2004 ◽  
Author(s):  
Lan Peng ◽  
Dan-Ling Zeng ◽  
You-Rong Li
Keyword(s):  
Numerical Simulation ◽  
Crystal Growth ◽  
Liquid Bridge ◽  
Function Method ◽  
Thermocapillary Convection ◽  
Numerical Study ◽  
Flow Profile ◽  
Float Zone ◽  
Physical And Mathematical Models

The physical and mathematical models of the thermocapillary convection in liquid bridge with liquid encapsulation are established in the present paper. A numerical simulation of the thermocapillary convection in liquid bridge with liquid encapsulation is performed by employed vorticity-stream function method and the Alternative Direction Implicit scheme in finite difference. The distribution of temperature and flow in liquid columns is then obtained. It is verified that liquid encapsulation can reduce the thermocapillary convection in liquid bridge and can improve the quality of crystal growth in float zone. The influence law of the thickness of liquid encapsulation on the thermocapillary convection in liquid bridge is obtained, the more thickness of liquid encapsulation decreases, the more the thermocapillary convection in the inner liquid and the outer liquid diminishes. It is found that the flow profile of two liquid columns is much more complex than that of single liquid column.

Thermocapillary convection in a model float zone

10.2514/3.302 ◽  
1991 ◽  
Vol 5 (4) ◽  
pp. 577-582 ◽  
Author(s):  
J. R. Hyer ◽  
D. F. Jankowski ◽  
G. P. Neitzel
Keyword(s):  
Thermocapillary Convection ◽  
Float Zone

Examination of Extra Electron Diffraction Spots Observed in Deuterium-Irradiated Silicon by Using Parallel Electron Beam Illumination

1990 ◽  
Vol 48 (2) ◽  
pp. 490-491
Author(s):  
Ryuichiro Oshima ◽  
Shoichiro Honda ◽  
Tetsuo Tanabe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Single Crystal ◽  
Mixed Solution ◽  
Parallel Beam ◽  
Defect Clusters ◽  
Float Zone ◽  
Transmission Electron ◽  
Extra Electron ◽  
Diffraction Patterns

In order to examine the origin of extra diffraction spots and streaks observed in selected area diffraction patterns of deuterium irradiated silicon, systematic diffraction experiments have been carried out by using parallel beam illumination.Disc specimens 3mm in diameter and 0.5mm thick were prepared from a float zone silicon single crystal(B doped, 7kΩm), and were chemically thinned in a mixed solution of nitric acid and hydrogen fluoride to make a small hole at the center for transmission electron microscopy. The pre-thinned samples were irradiated with deuterium ions at temperatures between 300-673K at 20keV to a dose of 1022ions/m2, and induced lattice defects were examined under a JEOL 200CX electron microscope operated at 160kV.No indication of formation of amorphous was obtained in the present experiments. Figure 1 shows an example of defects induced by irradiation at 300K with a dose of 2xl021ions/m2. A large number of defect clusters are seen in the micrograph.

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