ABSTRACTA semi organic nonlinear opticalcrystal of Bis thiourea Zinc acetate (BTZA) has grown by slow evaporationtechnique. The raw material for the growth of BTZA was synthesized by 1:2 molarratio in de-ionized water. The crystal system and lattice parameters determinedfrom X-ray diffraction.
Fourier transform infrared studies confirm the variousfunctional group present in the grown crystal. TheUV-Visible spectrum absorbance and transmittance was recorded in the wavelengthrange of 190–1100 nm. The absorption reveals that the lower cutoff wavelengthis 230nm.
Thethermal behavior of the grown crystal and noncentrosymmetric space group. Thedielectric constant and dielectric loss has been studied and varioustemperatures and the result were discussed. The SEM analysis was the surfacemorphology of BTZA single crystal analysed. Key Word: BTZA, FTIR,UV-Visible, Vicker’s hardness test, Powder XRD, TG-DTA analysis. Introduction Now a days nonlinear opticalmaterials have various area of telecommunications and optical storage devices.
The NLO crystals have been found to perform many applications in opticalcommunications, optical information processing, optical computing high densitydata storage and laser fusion recations. In second order nonlinear opticalmaterials have recently attracted of their potential applications in emergingoptoelectronic devices. The inorganic NLO materials like KDP, ADP, L-arginineand L-arginine phosphate, Bisthiourea Zinc acetate, L-histidiniumtetrafluroborate, L-histidinium tetrafluroborate have gained significantattention in the last few years. In the present work the title compound wassuccessfully synthesized by Bisthiourea Zinc acetate in equimolar ratio. Thesingle crystal has been grown by slow evaporation solution growth techniqueusing water as the solvent.
The number of studies are available on thestructural/ crystalline perfection. Mechanical and optical behavior of thepresent compound. In view of NLO applications these studies were carried byXRD, Vickers microhardness and photoluminous (PL). the grown crystals arePXRD,FTIR,UV-Visible, refractive index, and SHG measurements and electricalstudies were discussed. These studies show high efficiency in NLO singlecrystals.
ExperimentCrystalgrowth BTZA single crystals weresynthesized using thiourea and Zinc acetate in deionized water bystoichiometric ratio 1:2 of the chemical recation.2CS(NH2)2 + Zn(CH3COO)2 ZnCS(NH2)2 (CH3COO)2The solution wasstirred using magnetic stirrer and the mixture was heated upto 50°C todecomposition of the solute molecules. The thiourea coordinating from differentphases of metal-thiourea complexes, purity of synthesized salt was improved byrecrystallization process. The single crystal pure of BTZA was harvested in aperiod of 30 to 40 days of grown crystal. Fig.
1: ThePhotograph of BTZA Single crystalCharacterization SingleCrystal X-Ray diffraction AnalysisThe single crystalX-Ray diffraction has been using Bruker D8 venture diffractometer. The unitcell parameters in determined by APEX2 program. The single crystal diffractionanalysis of pure BTZA single crystal reveal that the compound crystallizes inmonoclinic system.
The lattice parameters for pure BTZA are a=7.17 Å, b=17.80 Å,c=11.23 Å and ?=?=90?, ?=103.21? and cell volume V=1396Å3respectively.PowderX-Ray Diffraction Analysis Fig 2.
Powder X-ray diffraction pattern of pure BTZAcrystalThe sample of thegrown crystal was subjected to powder X-ray diffraction analysis using analytical.Xpert PRO powder X-ray diffractrometer employing CuK? radiation (?=1.5405Å).the XRD pattern of pure BTZA crystal shown in figure.2.
the observed peaks inspectrum indicated the resemblance of grown crystal to monoclinic structure.The evaluated cell parameters are a=14.431 Å, b=5.340 Å, c=10.981 Å.
and ?=?=90?, ?=103.37?respectively.FTIRAnalysisFig 3.
FTIR Analysis ofBTZA Single CrystalThe infraredspectroscopy used to identify the functional groups of the samples FTIR spectraof pure BTZA single crystals were recorded in the KBr pellet technique. Thefrequency region from 400-4000 cm-1 ranges using perkin elmerspectrometer. The FTIR spectra comparision of the grown crystals is shown inthe table1 & figure 2. The FTIR spectrum of pure BTZA with the spectra ofthiourea a shift in the peak was observed, the confirmed metal coordinationwith thiourea.
The N-H vibration bands in the high frequency range from3000-3400cm-1. It indicates that the bonding is between sulphur andzinc atoms, the peaks at 2751cm-1 for pure BTZA and the band 1644cm-1which are assigned C=N stretching vibration. The appearance of peak 1406 and1043cm-1 for pure BTZA single crystals.
In absorption of pure C-Sand C-N strectching frequency of complex formation. In pure BTZA singlecrystals of symmetric and asymmetric vibrations at 932 and 775cm-1respectively. The FTIR studies shows that in the spectra BTZA is a frequencyband in the lower frequency band in the lower frequency region of BTZA singlecrystals.Table 1FTIR data of Pure BTZA singlecrystal Pure BTZA Wavenumber (cm-1) Assignment 3375 N-H Stretching 2751 C-H Stretching 1644 C-N Stretching 1406 Asymmetric C=S Stretching 1043 C-N Stretching 932 C-O-H Bending 775 Symmetric C=S Stretching UV-Visible analysisTheUV-Vis spectrum of pure BTZA single crystal was recorded in the range of200-1100nm. The instrument used was LAMBDA-35 UV-Vis spectrophotometer. Theoptical study for SHG, the material is good transparent in the wavelengthregion for NLO material.
The transmittance is found to be maximum in thevisible near infrared region. In pure BTZA single crystal is found to be 80% transmittancewavelength. The lower cutoff frequency was at 270nm in pure BTZA singlecrystals for the opto electronic applications.Fig 4. UV-Visible transmittance ofBTZA CrystalMicrohardnessmeasurementVickers microhardnesstest is used to hardness of the material. The hardness number has to beevaluated of the load applied and the cross-sectional area of the depth of theimpression.
The Smooth surfaces of a grown pure BTZA crystals. The Vickershardness value is calculated from the formula:Hv = 1.8544*(p/d2)kg/mm2Where p is the appliedload in kg and d is the average diagonal length in millimeters of theimpressions in the present study. The Vickers hardness was measured usingLeitz-Wetzler hardness tester in different load is shown in fig.
4. it isobserved that the microhardness increases with the increase of load at lowervalues to the work hardness of the surface layers. At higher loads 100g themicrohardness shows a tendency to surface.Fig.
5. Hardness Vs loadgraph of pure BTZA crystalEDAXAnalysis Fig 6. EDAX spectrum of pure BTZA crystalEnergydispersive X-ray analysis for characterizating the elements was present in thegrown crystal.
EDAX analysis carried outusing JEOL-6360 scanning electron microscope. The recorded sepectrum is shownfig.5. The presence of carbon, nitrogen, nickel, oxygen, slphur and zincelements show incorporation of Pure BTZA grown crystal.
Thermal AnalysisTGA/DSCFig.7Thermal analysis of TGA/DSC pure BTZA crystal The thermal stabilityand physicochemical changes of BTZA single crystal were studied by thermogravimetric analysis and differential scanning calorimetric analysis. The curveof BTZA shown in fig.7.
TGA/DSC. The thermal decomposition starts at 199.2?Cthe acetate complexes with inorganic ligends the decomposition of thioureamolecules and the decomposition of the Zinc acetate and metal oxides. Thethermal decomposition of BTZA is exothermic peak at 200?C in the DSC analysisshows the melting point of the complex on compared to other thiourea basedcomplex 250?C and the allythiourea metal halides to be thermal stability of theBTZA good quality in single crystal.
References1 G. Pabitha, R.Dhanasekaran; Optics & Laser Technology 50 (2013) 150–1542 C.Ramachandra Raja, K.
Ramamurthi, R. Manimekalai; Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy 99 (2012) 23–26 3 B. Uma, Rajnikant,K.Sakthi Muruges, S.Krishnan, B.Milton Boaz, Progress in Natural Science: Materials International 24 (2014) 378–3874 R.
Rajasekaran, R.Mohan Kumar, R. Jayavel, P. Ramasamy* Journal of Crystal Growth 252 (2003)317–3275 N.R.
Dhumane, S.S.Hussaini, V.G.
Dongre, Mahendra, D. Shirsat, Optical Materials 31 (2008) 328–3326 N.Renuka, N.
Vijayan, Brijesh Rathic, R. Ramesh Babu, K. Nagarajan, D. Haranath, G. Bhagavannarayana Optik 123 (2012) 189– 192.
7 E.Ilango, R.Rajasekaran, S.
Krishnan, V. Chithambaram,Optik 125(2014) 7113-71158 SubbiahMeenakshisundaram, S.Parthiban, N.
Sarathi, R. Kalavat G. Bhagavannarayana,Journal of Crystal Growth 293 (2006) 376–3819 M.Lydia Caroline,A.
Kandasamy, R.Mohan, S.Vasudevan Journal of Crystal Growth 311 (2009) 1161–116510 M. LydiaCaroline, S. Vasudevan Current Applied Physics 9 (2009) 1054–106111 T.
C. Sabari Girisun, S. Dhanuskodi, D.
Mangalaraj, J. PhillipCurrent Applied Physics 11 (2011)838-84312 J. MaryLinet,S.Jerome Das Physica B 406 (2011) 836–84013 V.Natarajan,M.
Arivanandhan, K.Sankaranarayanan, P.Ramasamy Journal of Crystal Growth 311(2009) 572–57514 N.Pattanaboonmee,P.Ramasamy, R.
Yimnirun, P.Manyum, Journal of Crystal Growth 314 (2011) 196–20115 Vijayan N, RameshBabu R, Gopalakrishnan R, Ramasamy P. Journal of Crystal Growth (2004) 267 646–53. 16 Mohan Kumar R,Rajan Babu D, Jayaraman D, Jayavel R, Kitamura K. Journal of Crystal Growth(2005) 275 1935–9. 17 Venkataramanan V,Dhanaraj G, Wadhawan V K, Sherwood J N, BhatHL.
Journal of Crystal Growth(1995) 154 92–7. 18 Caroline ML,Vasudevan S. Materials Chemistry andPhysics (2009) 113 670–4. 19 Girisun TCS,Dhanuskodi S, Vinitha G. Materials Chemistry and Physics (2011) 129 9–14. 20 Selvakumar S,Kumar SMR, Joseph G P, Rajarajan K, Madhavan J, RajasekarSa, et al.
MaterialsChemistry and Physics (2007) 103 153–7. 21 Uthrakumar R, VestaC, Raj C J, Krishnan S, Das S J Current Applied Physics (2010) 10 548–52. 22 Lydia Caroline M,Vasudevan S.
Current Applied Physics (2009) 9 1054–61.