Characteristics of large-sized ruby crystal grown by temperature gradient technique

Large ruby with the size of ∅75 × 45 mm was grown by temperature gradient technique for the first time. Absorption spectrum was carried out in the range of 190-800 nm by spectrophotometer, and the concentration spatial distribution of Cr3+ in ruby was calculated from the absorption coefficient that based on the Beer-Lambert's Law. Cr3+ ions gradually increase along both the growth axis and the radial direction. The shape and ingredient of the inclusions were measured by means of Leitz wide field microscopy and scanning electron microscopy. Laue photos and X-ray omega scan show the good quality of as grown ruby. The optimized growth conditions were pointed out based on the observation.