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Investigation on the SR method Growth etching, birefringence, laser damage threshold and thermal characterization of Strontium bis (hydrogen L-malate) hexahydrate single crystal
|Senthil Arumugam 1, Ramasamy Perumal 2|
1. SRM University, Ramapuram, Bharathisalai, Chennai 600089, India
In recent years the search for new nonlinear optical materials included semi-organic and coordination compounds due to their advantages over traditional inorganic and organic compounds. Semi-organic materials possess several attractive properties such as high damage threshold, wide transparency range, less deliquescence and high nonlinear coefficient, which make them suitable for frequency doubling. Dicarboxylic acids have attracted the specific attention of many researchers for long time due to their overwhelming practical applications in science and technology. The growth and characterization of metal complexes of dicarboxylate crystals like oxalates, malonates, maleates and substituted acids like tartrates and lactates caught major attention due to their optical and ferroelectric properties. L-malic acid (C4H6O5) is one of the simplest chiral dicarboxylic acids, is a suitable building block in crystal engineering. Its chirality ensures the absence of a center of symmetry, essential for optical nonlinear second harmonic generation. Ammonium malate, racemic potassium malate, zinc malate 1,10-phenanthroline and cesium hydrogen malate are the famous reported semi-organic malic acid family crystals. The low-temperature solution growth is an important technique because large-size nonlinear optical and other crystals are being grown by this technique. In order to grow large crystals one has to ensure that, during the growth period, the available nutrient is deposited on the chosen seed only. Any spontaneous nucleation occurring during the growth will eat away a portion of the solute, thus making it difficult or impossible to grow a single large crystal. Crystals of different orientations with different morphology are grown by conventional solution growth technique but for application point of view, specific orientation with good quality is needed. The Sankaranarayanan–Ramasamy solution growth technique is suitable to grow high-quality large-size unidirectional L- Malic acid single crystals from solution. In the present investigation, semi-organic, good quality single crystals of strontium bis (hydrogen L-malate) hexahydrate (SrLM) were successfully grown by unidirectional SR method. Optically transparent SrLM crystal was grown by conventional slow cooling solution growth technique Based on the morphology of the conventional slow cooling grown SrLM crystal, the (010) plane was selected in the present study to impose the orientation in the growing crystal. The seed crystal started to grow after 12 days with growth rate of 1 mm/day. By this method, SrLM crystal with the diameter 10 mm and 50 mm length was grown in 34 days. The structural perfection and growth features of SrLM was analysed by chemical etching studies. The grown crystals were characterized by UV-Vis-NIR spectrum, birefringence, laser damage threshold and Thermal analysis (TG/DTA) studies. The UV-vis-NIR spectrum elucidates that the crystal is transparent between 230- 1100 nm and the lower cutoff is found to be around 226 nm. The value of birefringence and quality were ascertained by birefringence interferometer. The birefringence interferogram shows good refractive index homogeneity of the SrLM crystal grown by SR method. Optical damage tolerance of SR grown SrLM crystal was investigated by laser damage threshold studies. Laser damage value has been determined using Q-switched diode array side pumped Nd:YAG laser operating at 532 nm.
Presentation: Oral at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, General Session 2, by Senthil Arumugam
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17
Submitted: 2013-04-14 20:13 Revised: 2013-07-19 00:39