Growth and characterization of thiourea mixed cadmium – lead chloride – a nonlinear optical crystal

Abstract

Nonlinear optical (NLO) crystal of thiourea mixed cadmium-lead chloride dihydrate Cd[(PbCl 3 )(NH 2 CSNH 2 )].2H 2 O (TCCPC) have been grown in solution by slow evaporation technique at room temperature. The powder X-ray diffraction pattern has been recorded and indexed. The UV-Vis-NIR transmittance and FT-IR spectrum have been recorded in the range 200-1090 nm and 400-4000 cm -1 , respectively. The lower cut-off wavelength is 280 nm in the UV region, which is higher than that of pure Cd(PbCl 3 ) (CCPC) crystal. The presence of functional groups has been confirmed by FT-IR analysis. The TCCPC crystal was characterized by SEM and EDX spectrum. The second harmonic generation (SHG) of the thiourea mixed cadmium-lead chloride (TCCPC) crystal is demonstrated by the Kurtz Perry method using Nd:YAG laser and the results confirm that the grown crystal is roughly three times more efficient than ADP.

Effect of EDTA on the Growth Kinetics and Structural and Optical Properties of KDP Crystal

“…From optical transmission spectra it is seen that the addition of EDTA has increased the optical transparency as well as band gap of the crystal from 1.38 to 1.55 eV (Table 1). Since the material has good optical transmission characteristics in the wavelengths range 280-1090 nm, the material is suitable for generating second harmonics in the blue-green region [15].…”

Te(CS(NH2)2)4SO4·2H2O: A Three-in-One Semiorganic Nonlinear Optical Crystal with an Unusual Quadrilateral (TeS4)6– Chromophore

“…The reasonable application of acentric NLO-active groups, mainly including triangular ((BO 3 ) 3– , (CO 3 ) 2– , and (NO 3 ) − ) and tetrahedral ((BO 4 ) 5– , (BO x F 4– x ) ( x −1)– , (PO 4 ) 3– , (PO 3 F) 2– , (SO 4 ) 2– ) fundamental building units (FBUs), is of great significance for designing and synthesizing NLO crystals with excellent optical properties. − Particularly, due to the large microscopic second-order polarizability and giant optical anisotropy, the aforementioned π-conjugated planar triangular groups have been effectively used to synthesize crystals with large second harmonic generation (SHG) effect and birefringence. Notably, organic groups with similar π-conjugated configurations such as CO­(NH 2 ) 2 (carbamide), CS­(NH 2 ) 2 (thiourea = tu), [C­(NH 2 ) 3 ] + , (C 3 N 3 O 3 ) 3– , 4-hydroxypyridine, and so on are also alternative NLO-active FBUs. − For decades, the CS­(NH 2 ) 2 group with large dipole moment attracted sustained attention as an interesting FBU for linear or NLO materials . Because of its electroneutrality, this group has been widely used in the synthesis of semiorganic materials by combining them with other inorganic compounds. − The type of semiorganic material has usually been considered to possess the advantages of both organic and inorganic compounds .…”

“…Notably, organic groups with similar π-conjugated configurations such as CO­(NH 2 ) 2 (carbamide), CS­(NH 2 ) 2 (thiourea = tu), [C­(NH 2 ) 3 ] + , (C 3 N 3 O 3 ) 3– , 4-hydroxypyridine, and so on are also alternative NLO-active FBUs. − For decades, the CS­(NH 2 ) 2 group with large dipole moment attracted sustained attention as an interesting FBU for linear or NLO materials . Because of its electroneutrality, this group has been widely used in the synthesis of semiorganic materials by combining them with other inorganic compounds. − The type of semiorganic material has usually been considered to possess the advantages of both organic and inorganic compounds . Extensive investigation in this direction resulted in the discovery of a series of semiorganic NLO crystals, such as Zn­(CS­(NH 2 ) 2 ) 3 SO 4 , MgZn­(CS­(NH 2 ) 2 ) 3 SO 4 , Ba­(CS­(NH 2 ) 2 ) 2 (NO 3 ) 2 , and Cd­(CS­(NH 2 ) 2 ) 2 Cl 2 .…”