Characteristic of Raman Spectra, Crystal Structure and Superconductivity of Fe-Doped GdBa<sub>2</sub>Cu<sub>3-x</sub>Fe<sub>x</sub>O<sub>7-δ</sub> Systems

Abstract

The effects of Fe doping on the structure, electronic transport properties and Raman spectra of GdBa2Cu3-xFexO7-δ (x = 0.00-0.30) systems have been investigated. The analysis of X-ray diffraction patterns shows that the compound undergoes an Orthorhombic–Tetragonal (O-T) phase transition in the doping range of x = 0.05-0.10. The superconducting transition temperature Tc decreases with the increase of Fe doping level, whereas the superconducting transition width increases abruptly with O-T transition. We have discussed the Raman shifts and intensity of the five normal phonon peaks and some other peaks which result from the vibration of Cu(1) and O(1) oxygen for the Fe doped-samples. These investigations reveal that the electronic transport properties and Raman spectra of GdBa2Cu3-xFexO7-δ composites obviously depend on O-T transition induced by the Fe doping.