Growth, structural and optical studies on amino acid based new GSB crystals having non-linear optical characteristics

Transparent crystals of α-glycine with sodium nitrate and barium nitrate (GSB) have been grown from aqueous solution by slow evaporation technique at room temperature. Crystals of size 11 × 7 × 4 mm3 have been obtained in 3–4 weeks time. The solubility of GSB has been determined in water. The grown crystal belongs to orthorhombic system with cell parameters a = 4.684 a.u., b = 12.184 a.u. and c = 10.969 a.u. with unit cell volume of 625.99 (a.u.)3. Comparative IR and Raman studies indicate a molecule with a lack of centre of symmetry. A wide transparency window useful for optoelectronic applications is indicated by the UV studies. Using Nd–YAG laser (1064 nm), the optical second harmonic generation (SHG) conversion efficiency of GSB is found to be 0.648 times that of standard KDP. On exposure to light the GSB crystals exhibit positive photoconductivity. I–V characteristics, dielectrics studies and Vickers micro hardness measurement have been carried out. The GSB crystal exhibits more mechanical strength compared to the reported GSN crystals.

Research Highlights
► Wide Optical transparency window between 211 nm–900 nm.
► Powder SHG efficiency of 0.648 times that of standard KDP material.
► Non- centro symmetric crystal structure is indicated by IR and Raman analysis.
► Decrease in dielectric loss at high frequencies.
► Moderately hard material as compared to reported GSN useful in device fabrication.