Floating zone growth and defect study on ruby single crystals

Ruby single crystals with a diameter of 7 mm and a length of 70 mm were successfully produced by the floating zone technique. The solid-liquid interface is convex to the melt, and growth direction was determined as <001>. The X-ray rocking curve of the crystal has a FWMH of 0.089°, proving the excellent quality of the crystal. The as-grown crystals were characterized by polarized optical microscopy, X-ray diffraction, chemical etch, scanning electron microscopy, as well as energy dispersive spectroscopy. The primary crystal defects observed were bubbles, dislocations, cellular Structure and solute trails. The relationship between crystal quality and growth condition was also discussed, and the optimum method was obtained.