Float-zone crystal growth of CdGeAs2 in microgravity: numerical simulationand experiment

Two CdGeAs2 samples have been successfully grown under microgravity on SPAC EHAB-SH04 during the STS-77 Space Shuttle Endeavour mission. One polycrysta lline and one single crystal CdGeAs2 feed rods with 9 mm diameter were proc essed by the float-zone method. An eutectic salt of LiCl and KCl was used a s an encapsulant to suppl ess Cd and As evaporation from the melt. Numerica l modeling of the float zone shows that salt encapsulation plays an importa nt role in reducing Marangoni convection. The interface between the salt an d CdGeAs2 was shown not to deform in the float zone due to the weak capilla ry pressure. (C) 2000 Elsevier Science B.V. All rights reserved.