Revealing growth defects in non-linear borate single crystals by chemical etching

• Published in: Journal of crystal growth 2000-01, Vol.209 (1), p.102-109
• Main Authors: Péter, Á, Polgár, K, Beregi, E
• Format: Article
• Language: English
• Subjects: Chemical etching; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; CsLiB 6O 10 (CLBO); Defects and impurities in crystals; microstructure; Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.); Exact sciences and technology; Growth from melts; zone melting and refining; Growth from solutions; Li 2B 4O 7 (LTB); LiB 3O 5 (LBO); Materials science; Methods of crystal growth; physics of crystal growth; Physics; Structure of solids and liquids; crystallography; YAl 3(BO 3) 4 (YAB); β-BaB 2O 4 (BBO)
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(99)00515-1

Inorganic cyclic borates such as β-BaB 2O 4 (BBO), LiB 3O 5 (LBO), CsLiB 6O 10 (CLBO) and Li 2B 4O 7 (LTB) are excellent non-linear optical (NLO) materials, particularly in the ultraviolet region. Another type of borate is YAl 3(BO 3) 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.