Growth and Characterization of Pure and Thiourea-Doped L-Alanine Single Crystals for NLO Devices

We successfully grow single crystals of pure and thiourea-doped glycyl-L-alanine hydrochloride (GLAH and TU-GLAH) from aqueous solutions by the slow evaporation technique. We study the effect of thiourea dopant on the crystal properties. Single-crystal X-ray techniques confirm the crystal structure and change in the lattice-parameter values for the doped crystals. We analyze the doped crystals quantitatively by energy-dispersive X-ray analysis (EDAX) and confirm the presence of thiourea in the pure samples. We obtain the second-harmonic generations for the grown crystals using a Nd:YAG laser. We determine values of the work hardening coefficient from the microhardness study. We measure the values of the dielectric constant and dielectric losses in order to understand the electrical phenomena taking place in pure and TU-GLAH crystals.