The relationship between growth orientation and grain boundary generation in sapphire plate crystals grown by the EFG technique

Abstract Sapphire plate crystals used for substrates have been grown by the EFG technique. The experiments indicated that the generation of subgrain boundaries is closely related to the seed orientation. By choosing a favorable growth orientation, this imperfection can be obviously decreased. It is confirmed that the (0001) 〈11 2 0〉 slip system must be responsible for the generation of such grain boundaries.