Study on influence of growth conditions on position and shape of crystal/melt interface of alkali lead halide crystals at Bridgman growth

Suitable conditions for growth of high quality single crystals of ternary alkali lead halides prepared by a Bridgman method were explored using direct observation of a crystal/melt interface when pulling an ampoule out of a furnace, deliberated striations' induction and measurement of a temperature field in the filled ampoule in the vertical Bridgman arrangement, as model compounds lead chloride and ternary rubidium lead bromide were used. By direct observation only position of the crystal/melt interface was markedly determined, while by induced striations both the position and the shape of the interface were visualized but their contrast had to be intensified by adding admixtures. Performed temperature measurements in the filled ampoule brought both a view of temperature field in the 3D radial symmetry and basic data for comparison of a real temperature field with those obtained by projected modeling.

► Growth conditions for single crystals of ternary alkali lead halides.
► Study of position and shape of crystal/melt interface.
► Model compounds lead chloride and ternary rubidium lead bromide.
► Measured temperature field in 3D radial symmetry.