Morphology and formation mechanism of metallic inclusions in VB-grown sapphire crystals

作者：Taishi T^*; Kobayashi T; Shinozuka M; Ohba E; Miyagawa C; Hoshikawa K

来源：Journal of Crystal Growth, 2014, 401: 388-391.

DOI：10.1016/j.jcrysgro.2013.11.063

• Defect
• Inclusion
• Bridgman technique
• Growth from melt
• Sapphire
• Light emitting diodes

Morphologies of metallic inclusions observed in sapphire crystals grown by the vertical Bridgman (VB) technique using a tungsten (W) crucible were investigated. Square- or hexagonal-shaped inclusions 2-5 mu m in size were observed in sapphire crystals around the interface between the seed and the grown crystal. It was found that such inclusions consisted of W metal used for the crucible. The morphology of some of the inclusions reflects a rhombic dodecahedron which is based on the cubic structure of W and is surrounded by {110} faces. It is probable that inclusions form in the sapphire melt during the crystal growth process, and then sink in the melt to the growth interface due to the high density of W.

• 出版日期2014-9-1