Optical, mechanical and transport properties of unidirectional grown l-tartaric acid bulk single crystal for non-linear optical application

Good optical quality bulk single crystal of l-tartaric acid has been grown by directional solidification crystal growth method from aqueous solution. Crystal of dimension 77 mm length and 12 mm diameter has been grown at a growth rate of 2.5 mm day−1 which is the maximum size and growth rate achieved so far. The grown crystal was confirmed by powder XRD analysis and the presence of the functional groups in the crystal lattice was confirmed by Fourier transform infrared spectral analysis. Transmission spectral analysis shows that the crystal has more than 90% of transmittance in visible and near infrared region which exhibits the good optical quality of the crystal. The optical band gap was estimated to be 4.8 eV and it shows indirect optical transition. Thermal analysis shows the crystal to be thermally stable up to 172 °C and the load variation of the hardness has been explained on the basis of normal indentation size effect from microhardness study.

Research highlights▶ Single crystal of l-tartaric acid has been grown by unidirectional crystal growth method. ▶ The length and diameter of the grown crystal was 77 mm and 12 mm respectively. ▶ The grown crystal was confirmed by powder crystal X-ray analysis and FTIR analysis. ▶ The optical band gap was found to be 4.8 eV and the crystal is stable up to 172 °C. ▶ The microhardness study satisfies normal indentation size effect.