Bridgman growth of bismuth tellurite crystals

The photorefractive crystal, Bi₂TeO₅, was grown by the modified Bridgman method for the first time. High purity Bi₂O₃ and TeO₂ were used as starting materials and were mixed thoroughly with molar ratio of Bi₂O₃/TeO₂ = 1 ∶ 1. Platinum crucible was fabricated with a seed well of 10 mm in diameter and several folds were pressed so that the spontaneous nuclei could be eliminated through competition. The crucible was sealed during the growth so that the evaporation of TeO₂ was controlled effectively. By optimizing growth parameters, transparent and crack-free Bi₂TeO₅ crystal up to 25 mm in diameter and 40 mm in length was grown successfully.