A proper solution to study the etch pits on LiAlO2 single crystal

Detailed structures of the etch pits on the (1 0 0), (0 1 0), and (0 0 1) surfaces of LiAlO2 single crystals have been studied. The crystal was grown by the Czochralski-pulling technique. Hot water is found to be a good etching solution for LiAlO2 crystal. On the (1 0 0) surface, many shallow rhomboidal etch pits with a deep rhombic pit at the center are revealed and can line up to form boundaries. These etch pits are categorized into two groups which are symmetric relative to the [0 1 0] direction and are separated by boundaries made up of dense etch pits. On the (0 0 1) surface, square pyramid-like etch pits are present. However, rectangle-like etch pits are found on the (0 1 0) surface, which may not be related to dislocations. The density and the distribution of dislocations are studied. A scheme of the domain structure is proposed to explain the observed shapes and distributions of etch pits.