Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Physics

The para-quaterphenyl (p-4phenyl, C24H18) powder used in this work was obtained from the sigma aldrich company with purity 98%. The chemical structural of p-4phenyl in powder and thin film forms have been investigated by fourier transform infrared (FTIR) technique. The crystal structure of p-4phenyl in powder and thin film forms have been investigated by the X-ray diffraction at room temperature shows monoclinic structure. The unit cell parameters and the values of miller indices and lattice spacing corresponding to each diffraction line of p-4phenyl were estimated using some computer programs. p-4phenyl thin films have been deposited onto different substrates by thermal evaporation technique in a vacuum of the order 10⁻⁴ Pa and in a film thickness range of 243-1148 nm. The surface morphology of p-4phenyl thin films were studied by scanning electron microscope (SEM) at which the images of the deposited, annealed and irradiated p-4phenyl thin film shows, clearly almost uniform distribution of microcrystalline wire shaped- particles. Atomicforce microscope (AFM) image of the p-4phenyl thin films show that the grain size and the roughness of the surface decreased by annealing and gamma irradiation. The dark electrical resistivity u for the films of range 243nm-1148 nm were carried out at different temperature in the range 303 K-403K by using two point probe electrode

Issued also as CD