bonding have significant influences on linear and nonlinear optical properties of the molecules. Additionally, the microscopic origin of nonlinearity in the molecules is due to the presence of delocalized π electron systems connecting donor and acceptor groups which enhance the necessary asymmetric polarizability. Keeping the above mentioned statements in mind, the PNAPC molecule was considered as a potential NLO material. A number of papers reporting the theoretical and experimental investigations on the structure and vibration spectrum as well as the nonlinear
Ömer Tamer, Ahmet Sefa Atalay, Davut Avci, Yusuf Atalay, Erdoğan Tarcan and Mariusz K. Marchewka
I.S. Yahia, Mohd. Shkir, V. Ganesh, M.M. Abutalib, H.Y. Zahran and S. Alfaify
Herein, we report a successful development of nano-scale pure and Al and Mn co-doped PbI2 using facile microwaveassisted route. Structural study was done through X-ray diffraction analysis of grain size, dislocation density and lattice strain. The crystallite size was found to vary from 28 nm to 40 nm due to Al:Mn co-doping in PbI2. The presence of various vibrational modes was confirmed by FT-IR spectroscopy and red shifting was observed in peak positions compared to the bulk. Surface morphology, examined using a scanning electron microscope, confirmed the formation of single crystal nanosheets of a thickness in the range of 10 nm to 30 nm. The single crystal nanosheets were found to be transformed to large area nanosheets due to the doping. Enhancement in dielectric constant from ~7.5 to 11 was observed with increasing Al doping concentration. Linear attenuation coefficient was calculated and showed the enhancement of blocking gamma rays with increasing doping concentration. Its value was found to increase from 7.5 to 12.8 with the doping. The results suggest that the synthesized nanostructures can be used for detection and absorption of gamma rays emitted by 137Cs and 241Am sources.
A. Lakdja, I. Benzaidi, A. Sayede and A. Chahed
Lattice dynamic and mechanical properties of hypothetical RbC and SrC compounds were investigated using the ab-initio pseudopotential method and a linear response scheme. The lattice dynamics was studied in the framework of the density functional perturbation theory (DFPT). The dynamical and mechanical stability of the hypothetical RbC and SrC compounds was proved in their equilibrium B1 structure. In addition, the same stability was confirmed in the B3 phase. The thermodynamic properties were also investigated. They exhibited the same trend in both phases, and followed the Debye model. These results were confirmed in the ferromagnetic state, which makes the investigated compounds promising candidates in the spintronic field.
Surendra Singh, Anshuman Sahai, S.C. Katyal and Navendu Goswami
We have synthesized zinc-copper ferrite (ZCFO) employing exploding wire technique (EWT). The X-ray diffraction (XRD) data confirm the formation of single phase spinel ZCFO, which is in good agreement with Fourier transform infrared spectroscopy (FT-IR), UV-Vis, and Raman spectroscopic analyses. It is also clearly seen in the SEM micrographs that the grains in ZCFO ferrite are very rough, which allows adsorption of gas like oxygen and therefore, the material can behave as active sensing surface. The size range of the grains in prepared sample is of 200 nm to 500 nm. The FT-IR spectrum of the nanocomposite consists of two broad bands, one at 580.4 cm−1 due to M–O stretching mode at the tetrahedral site and the other at 400.7 cm−1 due to M–O stretching mode at the octahedral site. The nanoparticles show a UV-Vis absorption band in the wavelength region of 400 nm to 700 nm. The energy band gap for the prepared nanomaterial was estimated to be 3.16 eV. Thus, the ferrite nanocomposite prepared by EWT is optically active. According to present literature, Raman spectroscopy study on zinc-copper ferrite system has not been reported till date. By suitable attributing various Raman modes, we have further confirmed the formation of ZCFO nanophase through the present novel approach.
Meryem Evecen and Hasan Tanak
great accuracy in reproducing the experimental values of geometry, vibrational frequency, electronic absorption spectra, etc. [ 16 , 17 ]. In the previous publication, the X-ray crystallography and IR spectra of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate were studied [ 18 ]. In spite of its importance, mentioned above, no theoretical calculation concerning (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate has been published yet. The aim of this study is to investigate the spectral and structural properties of the
I. Md. Zahid, S. Kalaiyarasi, M. Krishna Kumar, T. Ganesh, V. Jaisankar and R. Mohan Kumar
shows the recorded infrared spectrum (400 cm −1 to 4000 cm −1 ) and Raman spectrum (4000 cm −1 to 500 cm −1 ) by using BRUKER IFS66VFT-IR and BRUKER RFS27 spectrometers, respectively. Fig. 5 Infrared and FT-Raman spectra of DSDMS. IR spectrum shows the prominent bands of ν (C=C) and ν (C–C) of aromatic ring at 1579 cm −1 and 721 cm −1 , respectively. Aromatic ring chain vibrations observed at 1576 cm −1 are due to C–C vibration in Raman spectrum. The vibrational bands of IR spectrum at 1040 cm −1 , 1176 cm −1 and 1164 cm −1 are assigned to ν
Mehmet Kara, Meryem Evecen and Telhat Özdogan
.  PAJAZK J., ROSPENK M., RAMAEKERS R., MAES G., GŁOWIAK T., SOBCZYK L., Chem. Phys., 278 (2002), 89.  ARIVAZHAGAN M., KRISHNAKUMAR V., JOHNXAVIER R., ILANGO V., BALACHANDRAN K., Spectrochim. Acta A, 72 (2009), 941.  VARASANYI G., Vibrational Spectra of Benzene Derivatives, Academic Press, New York, 1969.  SILVERSTEIN R.M., WEBSTOR F.X., Spectrometric Identification of Organic Compounds, 6th Ed., JohnWilley & Sons, New York, 1998.  COLTHUP N.B., DALY L.H., WIBERLY S.E., Introduction to
Ayaz Arif Khan, M. Javed, A. Rauf Khan, Yousaf Iqbal, Asif Majeed, Syed Zahid Hussain and S.K. Durrani
shows FT-IR spectra of investigated NiFe 2 O 4 samples which helps to confirm the synthesis of spinel structure. In infrared region, two main frequency modes are observed within the wave number range of 1000 cm −1 to 300 cm −1 . The higher band (ν 1 ), generally observed in the range of 600 cm −1 to 550 cm −1 , is attributed to the stretching frequency of tetrahedral metal-oxygen bond and the lowest band (ν 2 ), commonly observed in the range 450 cm −1 to 385 cm −1 , is assigned to vibration mode of octahedral metal-oxygen bond [ 37 ]. Fig. 3 FT-IR spectra
S. Karuna, A.R. Balu, S. Muthu, D. Shyamala, Z. Delci and G.R Ramkumaar
.Sci. Appl., 3 (2015), 32.  RIOS M.A., RODRIGUEZ J., Can. J. Chem., 71 (1993), 303.  KARABACAK M., KURT M., Spectrochim. Acta A, 71 (2008), 876.  JAMROZ M.H., Vibrational energy distribution analysis VEDA 4 Computer program, Warsaw, Poland, 2004.  DENNINGTON R.I., KEITH T., MILLAM J., EPPINNETT K., HOVELL W., GILLILAND R., Gauss View Version 3.09, Semichem Inc. Shawnee Mission, KS, USA, 2003.  LEE C., YANG W., PARR R.G., Phys. Rev. B, 37 (1988), 785.  BECKE
Rafal Chodun, Katarzyna Nowakowska-Langier, Sebastian Okrasa and Krzysztof Zdunek
. Deposited on silicon substrates AlN films were examined by SEM in terms of morphology of the structures with a ZEISS ULTRA Plus device. The samples were observed at a 45° angle. An estimation of the quality of the synthesized film surfaces in order to detect the metallic droplets was carried out by an optical microscope. Micro Raman studies of the synthesized layers were performed using the JASCO NRS-5100 device with Ar+ laser of 2.33 eV (532 nm) excitation energy. Meanwhile, vibrational spectra registering the 6.5 mW laser beam was focused onto 10 μm spots. 3