Taymour A. Hamdalla

Influence of Erbium Ions on the Optical and Structural Properties of Polyvinyl Alcohol

Polyvinyl alcohol (PVA) films doped with erbium chloride (ErCl3) have been prepared by casting from their aqueous solutions. The structure of the doped samples as well as the interactions between the host PVA and Er

FTIR and optical properties for irradiated PVA–GdCl3 and its possible use in dosimetry

ABSTRACT There are various chemical and physical changes caused when polymers are exposed to a source of radiation. In the present work, four films of polyvinyl alcohol (PVA) doped with 2, 4, 6 and 8 wt% of gadolinium chloride (GdCl3) have been irradiated by low-dose fast neutrons using Am-241/Be-9. The structural properties of the synthesized films have been investigated pre- and post-irradiation on the basis of Fourier transform infrared technique. The optical properties of the PVA–GdCl3 films have been investigated for doses up to 1.2 KGy. The energy gap of the synthesized films showed a neutron dose dependence and was decreased by 0.81 eV after exposing to 1.2 kGy. At a wavelength of 1000 nm, the refractive index of the PVA doped with 8 wt% GdCl3 has been increased by nearly 16%. The results suggested the possible use of PVA--GdCl3 as a dosimeter for the neutron beams.

Reflectivity of linear and nonlinear gamma radiated apodized chirped Bragg grating under ocean

In this paper, the effect Co60 gamma radiation is investigated on the effective refractive index of apodized chirped Bragg grating. Nine apodization profiles are considered. Comparison between the reflectivity of the gamma radiated and non radiated fiber Bragg grating has been carried out. The electric field of signals propagating through the apodized chirped fiber Bragg grating (ACFBG) is first calculated from which, new values for the refractive index are determined. The nonlinear effects appear on the ACFBG reflectivity. The effect of nonlinearity and undersea temperature and pressure on the grating is also studied.

Thin film assembly of nanosized cobalt(II) bis(5-phenyl-azo-8-hydroxyquinolate) using static step-by-step soft surface reaction technique: Structural characterization and optical properties

Nanosized (NS) cobalt (II) bis(5-phenyl-azo-8-hydroxyquinolate) (NS Co(II)-(5PA-8HQ)2) thin films have been synthesized using static step-by-step soft surface reaction (SS-b-SSR) technique. Structural and optical characterizations of these thin films have been carried out using thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray diffraction (XRD). The HR-TEM results revealed that the assembled Co(II)-complex exhibited a uniformly NS structure particles in the form of nanorods with width and length up to 16.90nm and 506.38nm, respectively. The linear and nonlinear optical properties have been investigated. The identified energy gap of the designed thin film materials was found 4.01eV. The refractive index of deposited Co(II)-complex thin film was identified by thickness-dependence and found as 1.9 at wavelength 1100nm. In addition, the refractive index was varied by about 0.15 due to an increase in the thickness by 19nm.