M. Caid, H. Rached, D. Rached, R. Khenata, S. Bin Omran, D. Vashney, B. Abidri, N. Benkhettou, A. Chahed and O. Benhellal
of all the elements, with strong hybridizations between the Te 5p and Te 5d states, as well as the Se 4p and Se 4d states.
In this section, we discuss the opticalproperties of a material that must be investigated to determine its potential usefulness in optoelectronic applications. For this reason, we only chose the materials that showed a direct band gap character in our LDA study. When examining the optical response of the compounds under investigation, it is convenient to take into account the transitions of electrons from the
Manuela-Maria Manziuc, Cristina Gasparik, Marius Negucioiu, Mariana Constantiniuc, Alexandru Burde, Ioana Vlas and Diana Dudea
an improved opticalproperty for applications as a dental ceramic. J Ceram Process Res 2011; 12: 473-476.
54. Kim MJ, Ahn JS, Kim JH, Kim HY, Kim WC. Effects of the sintering conditions of dental zirconia ceramics on the grain size and translucency. J Adv Prosthodont 2013; 5: 161-6.
55. Zhang HB, Kim BN, Morita K, Yoshida H, Lim JH, Hiraga K. Optimization of high-pressure sintering of transparent zirconia with nano-sized grains. J Alloy Compd. 2010; 508: 196-199.
56. Lucas TJ, Lawson NC, Janowski GM, Burgess JO. Effect of grain size on the
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 Cheoung WF, Welch A, Prahl S. A Review of the OpticalProperties
Optical properties of the zinc-cobalt oxide (ZnCoO) layers manufactured at different process conditions have been investigated. ZnCoO layers were grown on sapphire and glass substrates by pulsed laser deposition (PLD) technique. The influence of growth conditions as well as post-growth annealing on the films transmission and gap energy was analyzed.
electron transition and enhance the light absorption. However, it can also act as recombination centers [ 36 ].
Absorption spectra of pure TiO 2 , Mn/TiO 2 , S/TiO 2 and Mn–S/TiO 2 .
In order to explore the absorption properties, the optical absorption spectra of pure anatase TiO 2 , Mn/TiO 2 , S/TiO 2 and Mn–S/TiO 2 were calculated on the basis of the detailed electronic band structure as shown in Fig. 5 . Because of the underestimated band gap of pure TiO 2 , we induced a scissors operator of 1.032 eV (band gap
In this work, we studied with a Matlab program, some of optical properties of zinc oxide (ZnO) deposited on glass (SiO2). The parameters studied include the refraction index, extinction coefficient, optical band gap, and complex dielectric constant versus incident photon energy, and transmittance, absorbance and reflectance spectrum of ZnO thin film deposited on glass (SiO2) for different thickness. The films were found to exhibit high transmittance (75- 95%), low absorbance and low reflectance in the visible / near infrared region up to 1000 nm. However, the absorbance of the films was found to be high in the ultra violet region with peak around 380 nm.
D. Bensaid, M. Ameri, M. El Hanani, Y. Azaz, D. Bendouma, Y. Al-Douri and I. Ameri
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Refractive and birefringence indices in the range of transparency of 300 to 700 nm for triglycine sulphate crystals doped with D-serine molecules have been measured in the temperature range of 290 K to 340 K. The obtained optical properties are discussed together with characteristic electrical features of these materials used as pyroelectric sensors for measurement of temperature. The experimental results obtained in this study will be necessary as the reference data for comparison with the calculated refractive indices of TGS + D-serine on the basis of density functional theory. Determination of the proper position of D-serine, will reveal the features of TGS + D-serine crystal structure necessary to achieve stable unipolarity.
Shabeer Ahmad Mian, Muhammad Muzammil, Gul Rahman and Ejaz Ahmed
cubic structure [ 3 , 4 ]. Alkali halides are colored materials when exposed to radiation or impurity doping and thus they are used as detectors due to their strong scintillation effect  . Alkali halides are interesting materials in terms of their opticalproperties and often serve to test new theories  .
The physical properties of alkali halides (or mixed alkali halides) have been reviewed by Sirdeshmukh et al.  . The difference in atomic sizes between mixed crystals causes local stresses in lattice and changes crystal properties, particularly lattice
. 9 (2008), 2555.
7. Chiang C.Y., Aroh K., Franson N., Satsangi V.R., Dass S., Ehrman S.,in: Copper oxide nanoparticle made by flame spray pyrolysis for photo electrochemical water splitting -Part II. Photo electrochemical study, Int. J. Hydrogen Energy 36 (2011), 15519.
8.  Langford J.I. Louer D., High-resolution powder diffraction studies of copper (II) oxide,J. Appl. Crystallogr. 24(1991)149.
9. Abaker M., Umar, A. Baskoutas S., Kim S.H., Hwang S.W., in: Structural and opticalproperties of CuO layered hexagonal