This paper presents and compares three analytical methods for calculating low frequency band gap boundaries in doubly periodic arrays of resonating thin elastic shells. It is shown that both Foldy-type equations (derived with lattice sum expansions in the vicinity of its poles) and a self-consistent scheme could be used to predict boundaries of low-frequency (below the first Bragg band gap) ban...

In this paper, undopedZnO and Co-ZnOnano structureswith different molar ratio of Cobalt have been synthesized by the sonochemical method. Structure have been characterized by Fourier Transform (FTIR) and UV–Vis spectroscopy,Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Moreover, the direct band gap has been calculated by Tauc...

TiO2 nanopowder is prepared by simple sol-gel method using starting material as titanium isopropoxide with methanol and annealed at 600°C, 700°C and 800°C for 1 hour in air. X-ray diffraction pattern revealed the presence of both anatase and rutile phase in TiO2 specimens annealed at different temperatures. It is observed that the content of rutile phase and crystallite size increases with incr...

The SDS, PEG and CTAB roofed MgO nano powders were synthesized by co-precipitation method.  The sintered nano powders was shown Fm-3m space group with cubic phase obtained by the XRD pattern. The lattice strain was calculated to be used Williamson-Hall equations (W-H). The formation of Mg-O bond and hydroxyl radicals on the surface were confirmed by the FTIR analyses. The TEM revealed that the ...

Nanocrystalline titanium (iv) oxide paste has been deposited on Fluorine doped tin oxide glass substrate by the blade method. The deposited film was subjected to thermal treatment to obtain an electrode foe a photo-electrochemical cell. The electrode was sensitized with prophyrin dye which was a local dye extracted from carica papaya leaves. Avaspec 2.1 spectrophotometer was used to obtain the ...

Cu2ZnSnS4 (CZTS) thin films were prepared by directly sputteringCu (In,Ga)Se2 quaternary target consisting of (Cu: 25%, Zn: 12.5%, Sn; 12.5%and S: 50%). The composition and structure of CZTS layers have beeninvestigated after annealing at 200 0C, 350 0C and 500 0C under vacuum. Theresults show that recrystallization of the CZTS thin film occurs and increasingthe grain size with a preferred orie...

In this work, the effects of co-precipitation temperature and post calcination on the magnetic properties and photocatalytic activities of ZnFe2O4 nanoparticles were investigated. The structure, magnetic and optical properties of zinc ferrite nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetometry and UV–Vis spectrophotometry techniques.  The XRD re...