Transient dynamics and directional solidification in space platforms.
The impact of short impulsive forces on the semiconductor segregation patterns inside a generic mug Bridgman growth arrangement is discussed here with the help of a time-dependent 2D numerical scheme. Impulses have been applied parallel to the growth interface, equivalently, orthogonal to the external thermal gradient. The present results indicate that for each one of the three semiconductors considered, the reduced longitudinal and radial solid segregation are practically insensitive to the pulse shape, rectangular or half-sinusoidal. The reduced longitudinal segregation only depends on the growth velocity for constant g-dose impulses. The reduced radial segregation depends on both the interface growth velocity and very weakly on the activity time of the constant g-dose impulse externally applied. The thermal flux across the interface is shape-dependent and does not act synchronically with half-sinusoidal external impulses. Also, as before, this flux depends on the activity time and on the growth velocity for constant g-dose impulses.
Ruiz
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Applied Physics Laboratory, Facultat de Quimica, Universitat Rovira i Virgili, Campus San Pere Sescelades, 43007 Tarragona, Spain. josepxavier.ruiz@urv.net