Structure Deformation in GdCOB Single Crystals Grown by the Czochralski Method

• Published in: Crystal growth & design Vol. 8; no. 9; pp. 3253 - 3256
• Main Authors: Klos, Andrzej, Domagala, Jarosław Z, Bajor, Andrzej, Pajaczkowska, Anna
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 03.09.2008
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from melts; zone melting and refining; Inorganic compounds; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Calcium Borates; Fluctuations; Calcium oxide; Growth interface; Czochralski method; Lattice parameters; Gadolinium Borates; Gadolinium oxides; Monocrystals; Spatial distribution; Second harmonic; Optical properties; Growth mechanism; Instability; X-ray topography; Borates; Crystal growth from melts; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg7012232

Gadolinium calcium oxide borate GdCa4O(BO3)3 melts congruently, and single crystals with diameters of up to 35 mm and lengths of up to 70 mm were grown by the Czochralski method. Deformation of the crystal structure was observed. X-ray topography and conoscopic and polariscopic investigations revealed the core situated in the central part of the crystal, which was not visible with the naked eye. The relative (b/b av) difference in the lattice parameter b in the core region compared with the neighboring crystal areas was evaluated to be on the order of 9.6 × 10−4. Outside of the core region the mean value of the lattice parameter is constant, while fluctuations in spatial distribution of the Bragg angle were discovered. The effect of growth instabilities causes a certain deformation of the growth plane (interface). However, it did not disturb optical properties, and was quite a good crystalline area to yield a considerable second harmonic (532 nm) power in laser experiments.