Enhancement in crystalline perfection and opt...

Enhancement in crystalline perfection and optical transparency by doping of Ammonium oxalate in L-alanine crystals: A NLO Crystal

Author Name : Shish Pal Rathee*, Dharamvir Singh Ahlawat

INTRODUCTION: L-alanine (LA: H2NCH (CH3)COOH) is an amino acid NLO crystal having orthorhombic crystal structure with non-centro symmetric space group (P212121) having around one-third second harmonic generation (SHG) efficiency to that of potassium dihydrogen phosphate (KDP) [1,2]. It has been reported that the incorporation of dopants in crystals leads to the redistribution of electronic charge, which modify the electric-dipole-photon effect in the energy-matter interaction and make the crystals efficient for SHG [3-5]. Different research groups have studied the incorporation of ammonium oxalate in L-valine crystals and demonstrated that ammonium ions manipulate optical transparency of L-valline crystals in UV region by changing the dipole-allowed energy transitions [6-9]. Further our earlier publication correlates the enhancement in SHG efficiency, laser damage threshold with the crystal perfection achieved by MnCl2 doping in L-Alanine. However, no literature is available on the synthesis, growth and characterization of Ammonium oxalate doped L-Alanine. Therefore we made attempts to grow new semi-organic crystals of Ammonium oxalate doped L-Alanine.