Growing high-quality Bi12SiO20 crystals of large diameter (85 mm)

Conditions that ensure reproducible growth of 〈110〉-oriented perfect Bi12SiO20 (BSO) crystals by the low-thermal-gradient Czochralski technique, whereby the entire crystallization front is occupied by the (110) crystal face, have been determined with the aid of numerical simulations. Using the established regime, BSO crystals have been obtained with a diameter of 85 mm, a length of 200 mm, and a mass of 10 kg. The density of dislocations in the crystals does not exceed 10 cm−2, and the refractive index inhomogeneity is below 10−3.