‎ The possibility of symmetrical s-wave superconductivity in the honeycomb lattice is studied within a strongly correlated regime, using the Hubbard model. The superconducting order parameter is defined by introducing the Green function, which is obtained by calculating the density of the electrons ‎ . In this study showed that the superconducting order parameter appears in doping interval be...

The BiI.7Sbo.JSr..,.,cal.OlCuJ.IOy superconductors are prepared by sol·gel method and the effect ofW~ and MnOz additives on their properties are studied. Structural studies show that the find samples are homogeneous and are mainly composed of 2223 and lower percents of 2212 phases. Analysis ofthe X-ray diffraction patterns indicate that the penetration of~ ions into superconducting phase c...

To understand the mechanism of superconductivity in unconventional super onductors is one of the big challenges in the field of superconductivity. Based on the BCS theory, there is a direct relation between the pairing mechanism and the symmetry of the order parameter. Therefore, identification of the structure of the superconducting gap or the order parameter provides key information on the pa...

  Samples of YBa2Cu3-xAgxOy with x=0, 0.1, 0.15, 0.2, 0.3 and samples of YBa2Cu3-xAlxOy with x=0, 0.01, 0.02, 0.03 and 0.045 are prepared by the sol-gel method. Structural and superconducting properties of samples are studied by electrical resistivity (R-T), X-ray diffraction (XRD) and scanning electron microscopy (SEM). All the samples show transition to superconducting state and the transitio...

In this paper, the role of radiation elements in the performance of reflect array antenna is studied, and each element is designed and simulated and the phase response is compared. Also, the relations needed for designing reflect array antenna are discussed and one sample reflect array antenna is designed in the KU band and the results are presented.