화학공학소재연구정보센터
Journal of Crystal Growth, Vol.209, No.1, 102-109, 2000
Revealing growth defects in non-linear borate single crystals by chemical etching
Inorganic cyclic borates such as beta-BaB2O4 (BBO), LiB3O5 (LBO), CsLiB6O10 (CLBO) and Li2B4O7 (LTB) are excellent non-linear optical (NLO) materials, particularly in the ultraviolet region. Another type of borate is YAl3(BO3)(4) (YAB) which is utilized as a laser host and for self-frequency doubling. Growth imperfections causing scattering and absorption of laser beams affect the performance and the use of borate single crystals. Defects, like inclusions, twins, grain boundaries and dislocations form readily in crystals grown by both the high temperature top-seeded solution growth (HTTSSG) method (BBO, LBO, YAB) and the Czochralski technique (CLBO, LTB). Chemical etching methods have been developed on various planes of the different borate crystals, in order to reveal the nature and the distribution of these defects. These methods have successfully been used to characterize NLO borate crystals. The origins of lattice defect formation are discussed in terms of the growth parameters.