BULK DEFECTS IN VAPOUR-GROWN CRYSTALS OF A4B6AND A2B6 SOLID SOLUTIONS

摘要

Factors governing the development and morphology of the bulk defects in single crystals:inclusions, microvoids, L-pores, secondary-phase separations on the surface have been studied.The dependences of growth processes parameters on structural properties of single crystals havebeen established. Relationship between the microvoid density and morphology of small angleboundaries and grain boundaries in crystal has been determined. Based on the above studies,recommendations for the optimization of conditions for vapour-growth of structurally perfectA~B~6,A~2B~6crystals, whereby said bulk defects are absent and dislocation density isNd < 104CM-2have been elaborated.