Growth and Characterization of Bisthiourea Nickel Bromide—New Semiorganic Nonlinear Optical Crystal

R S Sundararajan,C Ramachandraraja,M Senthilkumar

doi:10.4236/jcpt.2013.32008

Abstract

A new semiorganic nonlinear optical crystal of bisthiourea nickel bromide (BTNB) was grown successfully by slow evaporation technique using water as solvent. The lattice parameters of the grown crystal have been determined by X-ray diffraction studies. Vibrational spectrum is recorded to determine symmetries of molecular vibrations. Optical absorbance spectrum recorded revealed that this crystal has good transparency in the visible region. The second harmonic generation test of BTNB confirmed the nonlinear nature of the crystal. The BTNB crystal was analyzed by a differential thermal analysis and thermogravimetric analysis (DTA-TGA) to obtain its thermal stability. Vickers microhardness test done on the crystal shows that the crystal has greater physical strength.

Highlights

Nonlinear optical (NLO) frequency conversion materials have a significant impact on laser technology, optical communication and optical storage technology
In bisthiourea cadmium bromide (BTCB) the C-S stretching vibration was found at 1434 cm−1 whereas it was recorded at 1410 cm−1 for bisthiourea nickel bromide (BTNB)
The symmetric stretching band is recorded at 716 cm−1 and 726 cm−1 for BTCB and BTNB respectively

Summary

Introduction

Nonlinear optical (NLO) frequency conversion materials have a significant impact on laser technology, optical communication and optical storage technology. The search for new frequency conversion materials over the past decade has led to the discovery of many semiorganic NLO materials with high nonlinear susceptibilities. Among the semiorganic NLO materials metal complexes of the thiourea having lower cut off wavelengths, applicable for frequency conversion are of interest because both organic and inorganic components in it contribute to the process of SHG [1,2,3,4,5,6,7]. In the present work metal replacement is studied by taking a reported NLO crystal bisthiourea cadmium bromide [8]. The metal cadmium is replaced by nickel which is more active electro chemically

Experimental

Characterization

X-Ray Diffraction Studies

Analysis of IR Spectrum of Thiourea Vibrations in BTNB

Optical Transmission Spectrum

Conclusion