Accepted Manuscript Growth and characterization of organic material 4-dimethylaminobenzaldehyde single crystal R.P. Jebin, T. Suthan, N.P. Rajesh, G. Vinitha, U. Madhusoodhanan PII: DOI: Reference:

S1386-1425(14)01169-X http://dx.doi.org/10.1016/j.saa.2014.07.088 SAA 12508

To appear in:

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Received Date: Revised Date: Accepted Date:

1 April 2014 10 July 2014 29 July 2014

Please cite this article as: R.P. Jebin, T. Suthan, N.P. Rajesh, G. Vinitha, U. Madhusoodhanan, Growth and characterization of organic material 4-dimethylaminobenzaldehyde single crystal, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy (2014), doi: http://dx.doi.org/10.1016/j.saa.2014.07.088

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Growth and characterization of organic material 4dimethylaminobenzaldehyde single crystal R.P. Jebina, T. Suthana*, N.P. Rajeshb, G. Vinithac, U. Madhusoodhanand a

Department of Physics, Noorul Islam Centre for Higher Education, Kumaracoil - 629180, India b

Department of Physics, SSN College of Engineering, Kalavakkam - 603110, India c

Division of Physics, VIT, Chennai - 600175, India

d

Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam603102, India

Abstract The organic material 4-dimethylaminobenzaldehyde single crystals were grown by slow evaporation technique. The grown crystal was confirmed by the single crystal and powder X-ray diffraction analyses. The functional groups of the crystal have been identified from the Fourier Transform Infrared (FTIR) and FT-Raman studies. The optical property of the grown crystal was analyzed by UV–Vis–NIR and photoluminescence (PL) spectral measurements. The thermal behaviour of the grown crystal was analysed by thermogravimetric (TG) and differential thermal analyses (DTA). Dielectric measurements were carried out with different frequencies by using parallel plate capacitor method. The third order nonlinear optical properties of 4dimethylaminobenzaldehyde was measured by the Z-scan technique using 532 nm diode pumped continuous wave (CW) Nd:YAG laser. Keywords:

Organic compounds; Crystal growth; Optical properties; X-ray diffraction; Dielectric properties.

1

Corresponding author: Dr.T.Suthan Department of Physics Noorul Islam Centre for Higher Education Kumaracoil – 629180 Tamil Nadu, India Mobile: +91-9486783163 Email: [email protected], [email protected]

1. Introduction Recently, the crystalline organic materials are very much interesting because of their unique physical and chemical properties and their potential applications in many fields. In recent years, great attention has been paid to the development of materials for second order and third order nonlinear optical (NLO) applications, such as optical communications, optical switching, optical computing, data storage, dynamic holography, optical limiters, harmonic generators, frequency mixing etc [1-3]. The third order response governed by the second hyperpolarizability offers more varied and richer behaviour than the second-order NLO process due to the higher dimensionality of the frequency space [4]. In the centro-symmetric structures, non-substituted or symmetrically substituted organic compounds have been basically studied as third order NLO materials [5]. The, π conjugated organic materials have received considerable interest for their high nonlinear optical (NLO) properties and fast response time of the nonlinearity [6]. Particularly, the third order optical nonlinearities will play the essential roles in the high frequency ultra-fast optical processing techniques. The researchers are searching for new

2

promising third order nonlinear optical materials. The third order nonlinear optical properties were determined by using the Z-scan technique [7, 8]. It has been widely used in material characterization because it provides not only the magnitudes of the real part and imaginary part of the nonlinear susceptibility, but also the sign of the real part. The growth of high quality organic single crystals is a fundamental step in the investigation of the properties of a new material, and progress towards technological applications. There are different techniques have been proposed for the growth of organic single crystals, in the present study we used the solution growth technique. The 4-dimethylaminobenzaldehyde is a non-hygroscopic organic compound with molecular formula C9H11NO. The organic material 4-dimethylaminobenzaldehyde contains amine and aldehyde moieties. In both molecules, the aldehyde and dimethylamino groups are essentially coplanar with the attached benzene ring [9]. In the present study organic material 4dimethylaminobenzaldehyde single crystals have been successfully grown by slow evaporation technique using methanol as a solvent. The grown crystal were characterized by single crystal Xray diffraction, powder XRD, FTIR, FT-Raman, UV–Vis–NIR, photoluminescence, TG/DTA, dielectric measurements and third order nonlinear optic studies.

2. Experimental The 4-dimethylaminobenzaldehyde was commercially purchased. It has a molecular weight of 149.19 g/mol. Some molecular organic solids are very brittle and grow as very thin crystals that can be easily damaged on removal from the growth vessel. To overcome this suitable solvent has to be found. Organic crystal growth from solution mainly depends on the selection of solvents. The solubility was checked by different organic solvents and we optimised methanol as a suitable solvent. The solubility curve of 4-dimethylaminobenzaldehyde at different

3

temperatures from 30oC to 50oC is shown in Fig. 1. The solubility increases linearly with increase in temperature. The solvent was allowed to evaporate slowly at room temperature. The beaker containing the solution was optimally closed using a finely perforated polyethylene sheet for controlled evaporation. Transparent single crystals were obtained from the mother solution for few days. The purity of the grown organic single crystal was improved by successive recrystallization process. After a growth period bulk crystal of dimension of 6 x 4 x 1 cm3 were harvested from the mother solution with a time period of 15-20 days. The photograph of the grown 4-dimethylaminobenzaldehyde single crystals is shown in Fig. 2.

3. Result and discussion 3.1. Single crystal X-ray diffraction studies The grown 4-dimethylaminobenzaldehyde crystal was confirmed by single crystal and powder XRD analyses. The single crystal X-ray diffraction data were collected using Enraf Nonius CAD4-MV31 single crystal X-ray diffractometer. A suitable size single crystal was selected for the X-ray diffraction analysis and to estimate the cell parameters. The single crystal XRD result reveals that 4-dimethyaminobenzaldehyde single crystal belongs to monoclinic crystal system and the centro-symmetric space group P21/n. The observed unit cell parameters have good agreement with the reported values [9]. The obtained lattice parameters are shown in table 1. 3.2. Powder XRD studies Powder X-ray diffraction pattern of 4-dimethylaminobenzaldehyde crystal were recorded using powder X-ray diffractometer with CuKα1 radiation (λ=1.54060 Å). The powdered sample was scanned in the range from 10 to 70o. The powder X-ray diffraction pattern of the grown

4

crystal is shown in Fig. 3. The obtained (hkl) values are good agreement with the JCPDS file [10]. The well defined Bragg’s peaks at specific 2θ angles show the high crystallinity of the grown single crystal.

3.3. FTIR and FT-Raman spectral analyses FTIR and FT-Raman spectral analyses were carried out to analyze the functional groups of the grown 4-dimethylaminobenzaldehyde single crystal. FTIR were recorded using Perkin-Elmer FTIR spectrum RIX spectrometer by KBr pellet technique, with a range of 4000400 cm-1. The FT-Raman spectrum was recorded by using BRUKER-RFS 27 FT-Raman spectrometer in the range 3500-50 cm-1. The FTIR spectrum of 4-dimethylaminobenzaldehyde is shown in Fig. 4 and the FT-Raman spectrum of 4-dimethylaminobenzaldehyde is shown in Fig. 5. In IR spectrum the absorption peak at 2799 cm-1 is due to H–C=O stretching and the aldehydic C–H stretching absorption peak at 2707 cm-1 is to conform the presence of aldehyde group [11]. In FT-Raman spectrum the absorption peak at 2807 cm-1 is due to H–C=O stretching and the aldehydic C–H stretching absorption peak at 2736 cm-1 is to conform the presence of aldehyde group. In IR and Raman the peaks observed at 1666 cm-1 has been assigned to C=O stretching. The absorption peak at 1231cm-1 in IR and the absorption peak at 1244 cm-1 in Raman spectrum has been assigned to be C-N stretching. The peak absorbed in IR at 1598 cm-1 and the peak absorbed in Raman at 1588 cm-1 has been assigned to C-C stretching.

3.4. UV-Vis-NIR studies The optical transmittance range and transparency cut-off region are important parameters to tailor the material for specific device applications. Single crystals are mainly used for optical

5

applications. The UV-Vis-NIR spectrum of 4-dimethylaminobenzaldehyde was recorded using UV-Vis-NIR spectrophotometer in the range 200-1100 nm. Good transparent cut and polished single crystal with 2 mm thickness was used for the optical studies. The recorded spectrum is shown in Fig. 6. The result reveals that the grown 4-dimethylaminobenzaldehyde single crystal has more than 60% transparency and the cut-off wavelength is around 301 nm. The crystal is fully transparent through the entire visible region and the near IR region. It can be used as a window material for UV region and it is expected to be useful for nonlinear optical applications.

3.5. Photoluminescence studies Photoluminescence in solids is the phenomenon in which electronic states of solids are excited by light. Benzaldehyde derivatives have good photoluminescence property [12, 13]. The photoluminescence spectrum of the grown 4-dimethylaminobenzaldehyde single crystal have been recorded using the spectrofluorometer with 450 W high pressure Xenon lamp as excitation source. The observations are done at room temperature. The photoluminescence spectrum of the grown 4-dimethylaminobenzaldehyde single crystal is shown in Fig. 7. The highest intensity peak observed at 451 nm. The result indicates that the grown 4dimethylaminobenzaldehyde single crystal has blue emission and this suggests that it can be useful for new blue light emitting diodes.

3.6. Thermal studies The thermal behaviour of the grown 4-dimethylaminobenzaldehyde crystal was studied by thermogravimetric (TG) and differential thermal analyses (DTA) using SDT Q600 V20.9

6

Build20 instrument. For analyses, the temperature ranging from 35-500oC in nitrogen atmosphere at a heating rate of 10oC/min is being noted. The result obtained from TG and DTA are shown in Fig.8. In TG analysis a single sharp weight loss curve occurs and the material is stable up to 142oC. In DTA the first sharp endothermic peak is observed at 76oC, this indicates the melting point of the grown crystal. Before melting point there is no characteristic endothermic or exothermic peaks and there is no phase transition or decomposition up to the melting point. The second sharp endothermic peak observed at 249oC is assigned as the decomposition point. At this stage heavy weight loss in TG has been noticed and it indicates that it exactly coincides with the decomposition in TG analysis. Sharpness of the endothermic peaks observed in DTA indicates good degree of crystallinity of the sample.

3.7. Dielectric Studies: The dielectric constant is the basic electrical properties of solids. Dielectrics exhibit dipole structures where the dipoles will generally be in random orientations unless an electric field is applied. When a voltage is applied to a dielectric, the dipoles rotate and align themselves in the field so that electrical polarization occurs. The positive charges in a dipole are displaced minutely in the direction of lower voltage and the negative charges in the dipole are displaced minutely in the opposite direction [14]. The dielectric measurements were carried out by the Agilent 4284A LCR Meter using the conventional parallel plate capacitor Method [15-18]. The capacitance (Ccrys) and dielectric loss (tan δ) were measured

at

various

temperatures ranging from 308 to 343 K with four different frequencies 1 kHz, 10 kHz, 100 kHz and 1 MHz. The cut and polished transparent crystal of size 7 × 6 × 2 mm3

7

was used for dielectric measurements. The opposite faces were polished and coated with good conductive surface layer. The observations were made while cooling the sample. Air capacitance (cair) was also measured. The temperature dependence of the dielectric constant (εr), dielectric loss (tan δ) and AC conductivity (σac) at different frequencies are shown in Fig. 9 (a)–(c). Fig. 9 (a)–(c), it can be show that the dielectric parameters εr, tan δ and σac increase with increase in temperature. The εr and tan δ values decrease with the increase in frequency while the σac value increases with the increase in frequency. It shows that the grown crystal have the normal dielectric behaviour. The dielectric constant of a material is generally contributed by all the four polarizations namely, space charge, electronic, ionic and orientational polarizations. The space charge polarization is more dependent on the higher purity and defect free crystalline nature of a crystal; concurrently which actively influences at higher temperature due to temperature variation of polarizability [19, 20]. The electronic polarization and ionic polarizations are due to the displacement of electrons and ions respectively under an applied electric field and are temperature independent [21-23]. The orientational polarization occurs due to the alignment of permanent dipoles which are otherwise randomly oriented; under the action of electric field. Dependence of dielectric loss on frequency also can lead to polarization mechanisms. The low value of dielectric loss at high frequency implies that the crystal possesses good optical quality with lesser defects and this parameter is of more importance for NLO materials in their applications. 3.8. Nonlinear studies Organic materials exhibiting interesting third-order nonlinear optical properties are discussed. The Z-scan technique is a simple but very accurate method to determine both 8

nonlinear index of refraction n2 and nonlinear absorption coefficient β. Nonlinear index of refraction is proportional to the real part of the third-order susceptibility. (Reχ(3)) and the nonlinear absorption coefficient is proportional to (Imχ(3)) The Z-scan experiments were performed using a 532 nm diode pumped CW Nd:YAG Laser (Coherent CompassTM215M-50), which was focused by a 3.5 cm focal length lens. The laser beam waist at the focus is measured to be 15.84 µm and the Rayleigh length is 1.48 mm. A 1 mm wide optical cell containing the 4-dimethylaminobenzaldehyde sample in methanol is translated across the focal region along the axial direction that is the direction of the propagation laser beam. The transmission of the beam through an aperture placed in the far field was measured using photo detector fed to the digital power meter (Field master GS-coherent). For an open aperture Z-scan, a lens to collect the entire laser beam transmitted through the sample replaced the aperture. Fig. 10(a-c) gives a closed, open and ratio of the closed-to-open normalized Z-scan of 4dimethylaminobenzaldehyde sample in methanol at 60% transmittance. The peak followed by a valley-normalized transmittance obtained from the closed aperture Z-scan data indicates that the sign of the refraction nonlinearity is negative, i.e., self-defocusing. The self-defocusing effect is due to the local variation in the refractive index with the temperature. The measurable quantity ∆Tp-v can be defined as the difference between the normalized peak and valley transmittances, Tp − Tv. The variation of this quantity as a function of |∆φο| is given by (1)

∆T p−v = 0.406(1 − S ) 0.25 ∆φo

where ∆φ0 is the on-axis phase shift at the focus. S the aperture linear transmittance is given by S = 1 – exp (–2 r2a/ω2a)

(2)

9

with ra denoting the aperture radius and ωa denoting the radius of the laser spot before the aperture . The on-axis phase shift is related to the third order nonlinear refractive index (n2) [24] by, (3)

| ∆φ 0 | = kn2 Leff I 0

− αL where L eff = (1 − e ) / α , with L the sample length , α is the linear absorption coefficient IO is

the intensity of the laser beam at focus z = 0, and k is the wave number( k=2π/λ) The imaginary parts of the third-order nonlinear optical susceptibility [ χ 3 ] is estimated using the value of the nonlinear absorption coefficient β obtained from the open aperture Z-scan data and using the relations:

qo (z) =

β .I o .Leff (1 +

Z2 Zo

β=

2

(4)

)

2 2 .∆T I o .Leff

(5)

ZR = kω02 /2 is the diffraction length of the beam, ω0 is the beam waist radius at the focal point. Experimentally determined nonlinear refractive index n2 and nonlinear absorption coefficient β can be used in finding the real and imaginary parts of the third-order nonlinear optical susceptibility [ χ 3 ] [25] according to the following relations. 3

Re χ (esu ) = 10

−4

ε o c 2 no 2 cm 2 n2 ( ) W π

10

(6)

3

I m χ (esu ) = 10

−2

ε o c 2 n o 2 λ cm β( ) W 4π 2

(7)

where ε0 is the vacuum permittivity, and c is the light velocity in vacuum. The absolute value of the third-order nonlinear optical susceptibility is given by the relation

χ 3 = [( R e ( χ 3 )) 2 + ( I m ( χ 3 )) 2 ]

1/ 2

(8)

The nonlinear parameters calculated are as tabulated in Table 2.

4. Conclusion The 4-dimethylaminobenzaldehyde organic single crystal has been successfully grown by slow evaporation technique. The grown crystal was confirmed by single crystal and powder XRD studies. The functional groups present in the grown crystal have been confirmed by FTIR and FT-Raman studies. UV–Vis–NIR spectrum shows that the crystal has sufficient transmission

from

the

entire

visible

and near IR

regions. The

photoluminescence spectrum obtained in the present study indicates blue emission at 451 nm. Thermal studies show that the melting point of the grown crystal is 76◦C and below its melting point no phase transformation occurs. The results of dielectric measurements indicate that dielectric constant, dielectric loss and AC conductivity increase with the increase in temperature which can be understood due to the temperature variation of polarizability. The third order nonlinear shows that this 4-dimethylaminobenzaldehyde exhibits negative optical nonlinearity. The sample at 60 % transmittance exhibited non-linear refractive coefficient of the order of 10-8 (cm2/W), nonlinear absorption coefficient of the order of 10-4 cm/W and nonlinear susceptibility of the order of 10-6 esu. These results show that 4-dimethylaminobenzaldehyde crystal has potential applications for nonlinear optical devices.

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Reference [1] D.S. Chemla, J. Zyss, Nonlinear Optical Properties of Organic molecules and Crystals, Academic Press, New York, 1987. [2] L. Kuang, Q. Chen, E.H. Sargent, Z.Y. Wang, J. Am. Chem. Soc.125 (2003) 13648-13649. [3] Q. Chen, E.H. Sargent, N. Leclerc, A.J. Attias, Appl. Phys. Lett. 82 (2003) 4420-4422. [4] Asli Karakas, Huseyin Unver, Spectrochimica Acta Part A 75 (2010) 1492–1496. [5] Asli Karakas, Huseyin Unver, Ayhan Elmali, J. Mol. Struct. 877 (2008) 152-157. [6] A.S.L. Gomes, L. Demenicis, D.V. Petrov, Cid B. de Araujo, Celso P. de Melo, Rosa Souto‐Maior, Appl. Phys. Lett. 69 (1996) 2166-2168. [7] M. Sheik-Bahae, A.A. Said, T.H. Wei, D.J. Hagan, E.W. Van Stryland, IEEE, J. Quantum Electron 26, (1990) 760-769. [8] T. Thilak, M. Basheer Ahamed, G. Vinitha, Optik, 124 (2013) 4716-4720. [9] Bo Gao, Jian-Liang Zhu, Acta Crystallogr. Sect. E: Struct. Rep. 64 (2008) o1182. [10] JCPDS file card no.100-10-7. [11] R.M. Silverstein, G.C. Bassler, T.C. Morrill, in: Spectrometric Identification of Organic Compounds, Wiley, New York, 1991. [12] T. Suthan, N.P. Rajesh, J. Cryst. Growth 312 (2010) 3156-3160. [13] T. Suthan, P.V. Dhanaraj, N.P. Rajesh, Spectrochim. Acta Part A 87 (2012) 194-198. [14] Jalal Azadmanjiri, Christopher C. Berndt, James Wang, Ajay Kapoor, Vijay K. Srivastava, Cuie Wen, J. Mater. Chem. A 2 (2014) 3695–3708. [15] M. Priya, C.K. Mahadevan, Physica B 403 (2008) 67–74. [16] C. Krishnan, P. Selvarajan, T.H. Freeda, C.K. Mahadevan, Physica B 404 (2009) 289–294. [17] T. Suthan, N.P. Rajesh, P.V. Dhanaraj, C.K. Mahadevan, Spectrochim. Acta Part A 75

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(2010) 69-73. [18] T. Suthan, P.V. Dhanaraj, N.P. Rajesh, C.K. Mahadevan, G. Bhagavannarayana, Cryst. Engg. Comm. 13 (2011) 4018-4024. [19] K.V. Rao, A. Smakula, J. Appl. Phys. 36 (1965) 2031–2038. [20] K.V. Rao, A. Smakula, J. Appl. Phys. 37 (1966) 319–323 [21] A. Firdus, I. Quasim, M.M. Ahmad, P.N. Kotru, Bull. Mater. Sci. 33 (2010) 377–382. [22] S.K Arora, Vipul Patel, Brijesh Amin, Anjana Kothari, Bull. Mater. Sci. 27 (2004) 141–147. [23] M.P. Binitha, P.P. Pradyumnan, Bull. Mater. Sci. 37 (2014) 491–495. [24] T.D. Krauss, F.W. Wise, Appl. Phys. Lett. 65 (1994) 1739 – 1741. [25] T. Cassano, R. Tommasi, M. Ferrara, F. Babudri, G.M. Farinola, F. Naso, Chem. Phys. 272 (2001) 111-118.

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Table captions Table. 1 Single crystal XRD data for grown 4-dimethylaminobenzaldehyde Table. 2 Nonlinear parameters of 4-dimethylaminobenzaldehyde in methanol

Figure captions Fig. 1 Solubility curve of 4-dimethylaminobenzaldehyde Fig. 2 Photograph of 4-dimethylaminobenzaldehyde single crystals Fig. 3 Powder X-ray diffraction of 4-dimethylaminobenzaldehyde Fig. 4 FTIR spectrum of 4-dimethylaminobenzaldehyde Fig. 5 FT-Raman spectrum of 4-dimethylaminobenzaldehyde Fig. 6 UV-Vis-NIR spectrum of 4-dimethylaminobenzaldehyde Fig. 7 PL emission spectrum of 4-dimethylaminobenzaldehyde Fig. 8 TG/DTA spectrum of 4-dimethylaminobenzaldehyde Fig. 9 (a) Dielectric constants observed for 4-dimethylaminobenzaldehyde Fig. 9 (b) Dielectric loss factors observed for 4-dimethylaminobenzaldehyde Fig. 9(c)AC electrical conductivities (x 10-8 mho/m) observed for 4-dimethylaminobenzaldehyde Fig. 10 (a) Closed aperture (b) Open aperture (c) ratio of closed to open aperture z-scan

14

50 45 40

Weight in gm

35 30 25 20 15 10 5 30

35

40

45

50

o

Temperature( c)

Fig. 1 Solubility curve of 4-dimethylaminobenzaldehyde

15

Fig. 2 Photograph of 4-dimethylaminobenzaldehyde single crystals

16

(-410)

18000

15000

Intensity (a.u.)

12000

9000

6000

(911)

(012) (401) (320) (-421) (-420) (003)

(310)

(-411)

3000

0 10

20

30

40

50

60

70

80

Diffraction angle 2 θ

Fig. 3 Powder X-ray diffraction of 4-dimethylaminobenzaldehyde

17

100

(506)

(587) (718)

(933)

(2332)

(2707)

(2799)

60 (2904)

0 4000

3500

3000

2500

2000

(1366)

20

1500

(811)

(1231)

(1310)

(1160)

40

(1666) (1598) (1537)

Transmittance (%)

80

1000

500

-1

Wavenumber (cm )

Fig.4 FTIR spectrum of 4-dimethylaminobenzaldehyde

18

1588

6

4

355

1

174

2

833 726 633 596

1666 1552 1435 1312 1369 1244 1173 1124

70

3

3079 3016 2917 2807 2736

Raman Intensity

5

0 3500

3000

2500

2000

1500

1000

500

-1

Wavenumber (cm )

Fig.5 FT-Raman spectrum of 4-dimethylaminobenzaldehyde

19

80 70

Transmittance(%)

60 50 40 30 20 10 0 -10 200

400

600

800

1000

1200

Wavelength (nm)

Fig. 6 UV-Vis-NIR spectrum of 4-dimethylaminobenzaldehyde

20

300000

Luminescence Intensity (a.u.)

250000

200000

150000

100000

50000

0 350

400

450

500

550

Wavelength λ (nm)

Fig. 7 PL emission spectrum of 4-dimethylaminobenzaldehyde

21

-1 DTA TGA

100

-2 80

60 -4 40

-5

Weight (%)

Heat Flow (W/g)

-3

20

-6

0

-7

-8

-20 100

200

300

400

500

Temperature (°C)

Fig.8 TG/DTA spectrum of 4-dimethylaminobenzaldehyde

22

30 28 26 24

1 kHz 10 kHz 100 kHz 1 MHz

a

22

εr

20 18 16 14 12 10 8 305

310

315

320

325

330

335

340

345

Temperature (K)

Fig. 9 (a) Dielectric constants observed for 4-dimethylaminobenzaldehyde

23

0.7

b

1 kHz 10 kHz 100 kHz 1 MHz

0.6 0.5

tan δ

0.4 0.3 0.2 0.1 0.0 305

310

315

320

325

330

335

340

345

Temperature (K)

Fig.9 (b) Dielectric loss factors observed for 4-dimethylaminobenzaldehyde

24

c

1KHz 10KHz 100KHz 1MHz

2000

1000

-8

σac (x10 mho/m)

1500

500

0

305

310

315

320

325

330

335

340

345

Temperature (K)

Fig.9 (c)AC electrical conductivities (x 10-8 mho/m) observed for 4-dimethylaminobenzaldehyde

25

a

b

c

Fig.10 (a) Closed aperture (b) Open aperture (c) ratio of closed to open aperture z-scan

26

Table. 1 Single crystal XRD data for grown 4-dimethylaminobenzaldehyde Parameter

Literature [9]

Present study

a (Å)

10.356(6)

10.34

b (Å)

7.686(4)

7.69

c (Å)

20.8434(13)

20.87

α (o)

90

90

β (o)

96.808(13)

96.75

γ (o)

90

90

Volume Å3

1647.4(12)

1648

System

Monoclinic

Monoclinic

Space group

P21/n

P21/n

27

Table. 2 Nonlinear parameters of 4-dimethylaminobenzaldehyde in methanol --------------------------------------------------------------------------------------------------------------------n2

β

Re χ(3)

Im χ(3)

χ(3)

× 10 -8 cm2/W

× 10-4 cm/W

× 10-6 esu

× 10-6 esu

× 10-6 esu

---------------------------------------------------------------------------------------------------------------------7.9

-1.12

5.49

6.92

-8.84

---------------------------------------------------------------------------------------------------------------------

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4-Dimethylaminobenzaldehyde single crystal grown by slow evaporation technique.



Use methanol as solvent



Grown crystal conformed by XRD and FTIR.



Optical, thermal, dielectric and nonlinear optic studies were analyzed.

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Photograph of 4-dimethylaminobenzaldehyde single crystals

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Growth and characterization of organic material 4-dimethylaminobenzaldehyde single crystal.

The organic material 4-dimethylaminobenzaldehyde single crystals were grown by slow evaporation technique. The grown crystal was confirmed by the sing...
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