Pyrite FeS2 films are chemically deposited on quartz plates using the spray pyrolysis technique. Absorption coefficient data in the fundamental absorption region are analyzed and interpreted in terms of interband transitions. The electronic transitions in this region are in satisfactory agreement with the joint density of states estimated by Sato.

Articles you may be interested inMagnetron-sputter deposition of Fe3S4 thin films and their conversion into pyrite (FeS2) by thermal sulfurization for photovoltaic applications J. Vac. Sci. Technol. A 30, 04D102 (2012); 10.1116/1.3699022Opticalabsorption study of synthetic pyrite FeS2 single crystals

Abstract:In this paper, theoretical study of circular microstrip antenna loaded by two annular rings (CMSAL2AR) and calculation the contribution of the adjacent modes and studied positively or negatively affected on the antenna's coefficients (Bandwidth and Directive Gain).The proposed antenna using principle equivalence with moment of method formulation of electromagnetic radiation to find unknown electric current density on the conductor surface , and both unknowns electric and magnetic density current on the dielectric surface which are responsible for the generation of far fields radiation in the space for the components (E θ ,E φ ) . From the radiation pattern can be calculated with contribution of the adjacent mode. The directive gain increased to (G= 19.92 dB) and bandwidth has been better (BW%= 19.9%) when this contribution is affect positively at the ratioR ab =5.5 and R ab =6.5respectively.

This work aims to present a theoretical analysis of the electric and magnetic surface current densities of a circular microstrip antenna (CMSA) as a body of revolution.The rigorous analysis of these problems begins with the application of the equivalence principle, which introduces an unknown electric current density on the conducting surface and both unknown equivalent electric and magnetic surface current densities on the dielectric surface. These current densities satisfy the integral equations (IEs) obtained by canceling the tangential components of the electric field on the conducting surface and enforcing the continuity of the tangential components of the fields across the dielectric surface. The formulation of the radiation problems is based on the combined field integral equation. This formulation is coupled with the method of moments (MoMs) as a numerical solution for this equation.The numerical results of the electric and magnetic surface current densities on the outside boundary of a CMSA excited by - 11TM and - 21TM modes are presented. The radiation pattern is calculated numerically in the two principle planes for a CMSA and gives a good results compared with measured results published by other research workers.

A conformal antennas are plays an important role due to its multitasking possibilities , which have many opportunities in several applications. In this study, a new design of cylindrical rectangular microstrip antenna(CRMA ) excited at 〖TM〗_01 mode, was achieved in order to operate at the frequency of 5.6GHz. The simulation was done by Finite Difference Time Domain(FDTD) method using MATLAB program. The input impedance , return loss and radiation pattern of antenna were calculated and plotted. By using the slots technique and dual-layers substrate technique , the bandwidth(BW) is increased to 88.88% . Also BW is increased as the dielectric constant value is decreased.