In-situ observations of dissolution process of GaSb into InSb melt by X-ray penetration method

Abstract

a b s t r a c tDissolution process of GaSb into InSb melt was observed by an X-ray penetration method. The intensity of X-rays penetrated through the rectangular shaped GaSb (seed)/InSb/GaSb (feed) sandwich sample was recorded by the CdTe line sensor detector. The penetrated X-ray intensities and images of the sample were obtained as a function of time and temperature. The gallium (Ga) composition profile of the sample was calculated as a function of time by making the calibration line with the penetrated X-ray intensities of GaSb and InSb standard samples. The calculated Ga composition profile of the grown sample agreed well with the data measured by energy dispersive X-ray spectroscopy analysis. The result suggested that lower GaSb seed dissolved faster than upper GaSb feed despite of the low temperature at the lower GaSb seed. It clearly indicates that the solutal transport induced by gravity strongly affects the dissolution process.

Numerical Simulation of the Dissolution Process of GaSb into InSb Melt under Normal and Microgravity Conditions

“…Solutal Grashof number (GrC) Under normal gravity, the dissolution length at the seed was quite large compared with that at the feed as seen in the in-situ observation 7) by the X-ray penetration method and also in the computed values. Under microgravity, however, the dissolution lengths at the seed and the feed were very close to each other (dashed lines in the middle) due to the suppression of natural convection as expected; dissolution at the seed was reduced while that in the feed was enhanced.…”

“…The boundary condition used for temperature in this model is slightly different from that of the previous experiment 7) since the temperature on the outer edge of the ampoule could not have been controlled in the experiment. The related physical properties of In x Ga 1-x Sb, GaSb, BN and quartz 9,10) are given in Tables 1, 2, 3 and 4, respectively.…”

“…Preliminary experiments on Earth were performed previously [3][4][5][6][7] . Rajesh et al 7) carried out an in-situ observation of In x Ga 1-x Sb crystal growth in a furnace with temperature gradient along the growth ampoule.…”

“…Rajesh et al 7) carried out an in-situ observation of In x Ga 1-x Sb crystal growth in a furnace with temperature gradient along the growth ampoule. In this experiment, a cartridge of GaSb/InSb/GaSb sandwich structure was used, and the dissolution process of GaSb was examined by the X-ray penetration method 6) .…”

Numerical simulation of InGaSb crystals growth under microgravity onboard the international space station

“…This is mainly due to the suppression of convective flow in the solution (melt). Therefore, several experimental and numerical studies were performed for a better understanding of the InGaSb crystal dissolution and growth process by comparing the terrestrial and microgravity conditions [3][4][5][6][7][8][9]. Also recently Inatomi et al have compared the InGaSb crystals grown on the ISS and on Earth, and demonstrated that the shape of the growth interface was a slightly concave towards the seed under microgravity [10].…”