IOSR-JAP   Volume-12 ~ Issue-2 ~ Mar. – Apr. 2020

ABSTRACT: Thin films of Zinc Oxide nonostructures have been prepared by simple method and using spin coating technique deposited on ITO glass substrate. The study used different molars of zinc acetate 0.1 ,0.2 ,0.3 ,0.4 ,0.5 ,0.6 ,0.7 ,0.8 ,0.9 and1.0. The optical properties; including absorption coefficient, refractive index and energy bandgap were investigated by means of absorption, transmittance and reflectance spectra. Although, the refractive index has uncharacteristic behavior in the wavelength at the range 306 - 344 nm, the result showed the average value of refractive index for all samples is equal to 2.159. Also, the result confirmed that the nanostructure with concentration of 1.0 molar has lowest energy bandgap 3.44 eV and this may leed to highest coductivity comparing with other concentrations. This entire advantage make ZnO nanostrucures syntheised with 1.0 moalr of zinc acetate have wide range for solar cell applications.....

Keyword: ITO glass substrate, thin film , nanostructures, Optical properties.

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ABSTRACT: It is well known that Dirac relativistic equation describes the relativistic particle which is either free or move in any potential field. Even if one utilized the electromagnetic Hamiltonian which recognizes the effect of electromagnetic potential, the time dependent part of Dirac equation gives the same form which is free from the potential term if the potential is time independent. In this case the time dependent part gives a sine or cosine solution describing quantized string energy like that of harmonic oscillator but with no zero point energy. However if one follows De Broglie hypothesis and assumes that the string oscillator is in the form of a highly localized wave packet the time dependent part gives cosine solution with energy expression typical to that of Schrodinger equation which recognizes the existence of zero point energy. This means that when the wave packet islocalized in the form of a particle it has a rest mass energy corresponding to the zero point energy

Keyword: Klein Gordon equation, string theory, wave packet, harmonic oscillator, zero point energy, rest mass energy.

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ABSTRACT: In this work, Zinc Oxide nanoparticles (ZnO-NPs) were successfully synthesizedvia a facile sol-gel techniqueusingzinc acetate dehydrate, triethanolamine, ethanol and ammonium hydroxide. Characteristics of the as synthesizedZnO-NPs were studied via X-Ray diffraction (XRD), environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis,ultraviolet visible (UV-Vis) spectroscopy and photoluminescence spectroscopy. The XRD patterns confirmed the hexagonalwurtzite structure of ZnOwith lattice constant values, a = b = 3.2488 Å and c = 5.2054 Å. The average size of NPs estimated from ESEM images were in good agreement with the average crystal size obtained from the XRD data.The average particle size estimated from ESEM micrographs for sol-gel synthesis of ZnO-NPs was nearly......

Keyword: Sol-gel method, X-Ray diffraction, particle size, lattice strain, lattice constant.

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[4]. A. Amri, K. Hasan, H. Taha, M.M. Rahman, S. Herman, Andrizal, E. Awaltanova, I. Wantono, H. Kabir, C.-Y. Yin, K. Ibrahim, S. Bahri, N. Frimayanti, M.A. Hossain, Z.-T. Jiang, Surface structural features and optical analysis of nanostructured Cu-oxide thin film coatings coated via the sol-gel dip coating method, Ceramics International 45(10) (2019) 12888-12894.
[5]. M.D. Rao, P. Gautam, Synthesis and characterization of ZnO nanoflowers using Chlamydomonas reinhardtii: A green approach, Environmental Progress & Sustainable Energy 35(4) (2016) 1020-1026.

ABSTRACT: Lights of different polarizations have been used to measure the value ofn2 by using the polarization changeable Z-scan technique. The nonlinear refractive index n2 was measured for different concentrations of 2, 5-dimethylaniline in Chloroform. An Ar-ion laser was used with varying incident powers for three different wavelengths 457 nm,488 nm and 514 nm. The results give a negative n2 with a magnitude of the order of 10-6cm2/W. For all the wavelengths, the value of n2 was found to decrease with different states of lights i.e., linear, elliptical and circular polarized lights respectively, but the order of magnitude of n2 was the same.

Keywords: Polarization of light, Z scan, Nonlinear refractive.

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