Growth and Characterization of High-quality LiAlO_2 Single Crystal

γ-LiAlO_2 single crystal is a promising substrate for GaN heteroepitaxy.In this paper,we present the growth of large-sized LiAlO_2 crystal by modified Czochralski method.The crystal quality was characterized by high- resolution X-ray diffraction and chemical etching.The results show that the as-grown crystal has perfect quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec and etch pits density of(0.3- 2.2)×10~4 cm~(-2) throughout the crystal boule.The bottom of the crystal boule shows the best quality.The optical transmission spectra from UV to IR exhibits that the crystal is transparent from 0.2 to 5.5 #m and becomes completely absorbing around 6.7μm wavelength.The optical absorption edge in near UV region is about 191 nm.