Growth, structural, spectral, mechanical, thermal and dielectric characterization of phosphoric acid admixtured l-alanine (PLA) single crystals

Phosphoric acid admixtured l-alanine (PLA) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 18 mm × 12 mm × 8 mm have been obtained in 28 days. The grown crystals were colorless and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV–visible transmittance spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz–Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied.

The graphs were drawn using the software “ORGIN”. The digital data have been obtained and the graphs have been drawn.Figure optionsDownload as PowerPoint slideHighlights
► Our research group has been working for the past ten years in NLO crystals.
► Dr. P. Selvarajan and Dr. S. Perumal are the research guides and many scholars carry out the research under the guidance of them.
► In this article, we highlight the growth and various studies of phosphoric acid admixtured l-alanine (PLA) single crystals and from the studies it is noticed that the PLA crystal has the superior NLO property than l-alanine crystal.