Measurement of temperature fluctuations and microscopic growth rates in a silicon floating zone under microgravity

Analysis of microsegregation in RF-heated float zone growth of silicon—comparison to the radiation-heated process

“…In the crystal as well as the feed rod, the temperature gradient is nearly constant; the gradient at the solid-liquid interface amounts to 275 K/cm. Compared to the radiationheated process, this value is about a factor of 3 higher: For the radiation-heated case, the axial temperature distribution, measured in the center of a specially prepared sample using a Pt-PtRh thermocouple protected by an alumina capillary, revealed a gradient of 80-110 K/cm [15,16]. In the radiation-heated case, the temperature distribution is strongly non-linear and becomes smaller for reduced zone heights.…”

Simulation of microgravity floating-zone crystal-growth experiments in monoellipsoidal mirror furnaces

“…at Freiburg) [15], in a monoellipsoidal mirror furnace similar to the one used in the TEXUS 36 and MAXUS 4 experimental programmes [14,21], with semiaxes a=90 mm and b=80 mm. In this laboratory model the mirror was such that its reflectance was estimated to be around 0.8.…”

“…The simulation made in this work corresponds to the case where the sample is mounted in an ampoule, however, in the TEXUS and MAXUS programmes the sample can be also mounted in a steel cage [14,21]. In this wall-free configuration the sample is shaded by the inner holding ring, which causes a reduction in lamp irradiation (of the order of 30%; as shown by unpublished results) and a weakening of the heating effect of the secondary radiation; these two effects lead to a corresponding increase in lamp power (needed, for example, to obtain a given value of melt length).…”

TbFe2 giant magnetostrictive alloy prepared by drop-tube system

“…There are many approaches to achieve G conditions in utilizing an orbital space environment, for example, international space station (ISS), free flyer (FF) and space shuttle [13][14][15][16][17][18]. Those systems were more expensive than utilizing earth-based experiments, for instance, drop-tower and drop-tube system.…”