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Showing 3 results for Optical Properties.
Study of Structural, Morphological and Optical Properties of Magnesium Hydroxide Nanoplates Synthesized by Precipitation Route
S. Yousefi, B. Ghasemi, M. Tajalli, A. Asghari,
Volume 36, Issue 4 (3-2018)
Abstract
In this paper, high purity magnesium hydroxide nanoplates were successfully synthesized by using brine rich in magnesium ions as precursor and NaOH as precipitating agent without using dispersant agent in the room temoerature. The study and characterization of various properties of obtained nanopowder was carried out by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Fluorescence Spectrometer (EDX), Fourier Transform Infrared Spectrophotometer (FTIR) and Ultraviolet–visible spectroscopy (UV-Vis). The FESEM and XRD analysis results showed that magnesium hydroxide powder had nanoplates with the average crystallite size 17.1nm and no impurity; that was in agreement with the result of EDX and FTIR perfectly. Furthermore, optical characteristics of magnesium hydroxide nanoplates by UV-Vis spectroscopy showed an optical band gap of 5.5 eV. This wide band gap can be a useful innovation in optoelectronic sub-micron devices.

Effect of Annealing Temperature on the Structural, Magnetic and Optical Properties of SrCo2Fe16O27 Hexaferrite Nanostructure
N. Alirezaei Varnosfaderani, S. E. Mousavi Ghahfarokhi, M. Zargar Shoushtari,
Volume 38, Issue 3 (12-2019)
Abstract
In this paper, W-type SrCo2Fe16O27 hexaferrite nanostructures were synthesized by sol-gel auto-combustion method. Effect of annealing temperature on the structural, magnetic and optical properties of these SrCo2Fe16O27 nanostructures was investigated. In order to determine the annealing temperature of samples, the prepared gel was examined by thermo-gravimetric and differential-thermal analyses. Morphology and crystal structure of the prepared samples were characterized by field emission scanning electron microscopy and X-ray diffraction pattern. Based on X-ray diffraction results, at annealing temperature of 1000 °C, the maximum amount of main phase formed. A planar morphology was spectroscopy for the synthesized samples through scanning electron microscope images. Fourier transform infrared analysis was used to confirm the synthesis of the main properties obtained of samples were measured by the vibrating sample magnetometer and the results showed that by increasing temperature, magnetic saturation increases. Moreover, optical properties of samples were investigated by ultraviolet–visible absorption and photoluminescence spectroscopies. The result of measurements of the energy gap approximately is same in the ultraviolet- visible and photoluminescence spectroscopes and also the energy gap is constant with increasing temperature.

Ab-Initio Study of Optical and Magnetic Properties of Tungsten Disulfide
H. Salehi, N. Zhulayi Bakhoda, P. Amiri,
Volume 38, Issue 4 (1-2020)
Abstract
In this research, the optical properties of tungsten disulfide including dielectric function, the static refractive index, the imaginary part of the dielectric function, optical band gap, energy loss spectrum and its magnetic properties have been studied. Calculations have been done by using Quantum Espresso package which is based on density functional theory and pseudo-potential technique. The static refractive indices of this compound at diffrent x and z directions were calculated 3.66 and 2.55, respectively. The amount of optical band gap, obtained from the imaginary part of dielectric function, was estimated to be 1.45 eV. In addition, bulk plasmon energy, obtained from energy loss spectrum at x and z directions, were obtained to be 17.95 eV and 17.25 eV, respectively.

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