Growth and characterization of lead bromide: application to mercurous bromide
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Abstract
Mercurous Bromide (Hg2Br2) crystals hold promise for many acousto-optic and opto-electronic applications. Thismaterial is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects ofsolutal convection the crystal growth rate in a horizontal configuration for difusive-convection conditions and purelydifusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factorof one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 g0, the growth rate pattern exhibitsrelatively flat which is intimately related to difusion-dominated processes. The growth rate nonuniformity is regardles ofaspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in thegravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 bya factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.
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