Growth of negative solubility lithium sulfate monohydrate crystal by slow evaporation and Sankaranarayanan–Ramasamy method

Single crystals of negatively soluble lithium sulfate monohydrate (LSMH) have been grown by conventional and Sankaranarayanan–Ramasamy (SR) methods. A negatively soluble material has been grown for the first time by the SR method. The size of the grown crystal is 40 mm length and 15 mm diameter. The solubility of the material has been found at different temperatures. The grown crystals were subjected to high resolution X-ray diffraction studies, UV–vis analysis, dielectric measurements, Vickers micro-hardness, piezoelectric measurements, laser damage threshold and second harmonic generation studies. Crystalline perfection of the grown crystals was analyzed using HRXRD. The grown crystals were found to be transparent in the entire visible region. The SR method grown crystal has higher hardness, lower dielectric loss, higher piezoelectric charge coefficient and higher laser stability compared to the conventional method grown crystal. The powder Kurtz method confirms that LSMH has SHG efficiency.

► Bulk growth of negatively soluble lithium sulfate monohydrate has been achieved.
► High crystalline perfection and laser damage threshold have been achieved.
► High d33 is observed in unidirectional crystal compared to conventional crystal.