Weak Field Magnetic Susceptibility Fluctuations Above the Superconducting Transition YBa_{2} Cu _{3-x} Fe _{x} O _{7-\delta }(0.05 \le x \le 0.12)

This paper reports the production of YBa2Cu3-xFexO7-delta (0.05 <= x <= 0.12) superconducting system by using the standard solid-state reaction technique. A Rietveld refinement of the experimental X-ray diffraction patterns allows the determination of the lattice parameters and the phase composition of the studied system; the mean present phase shown is an orthorhombic phase Pmmm. Magnetic and transport properties are typical for superconducting samples. In this paper, magnetic susceptibility fluctuations are studied in the limit of weak magnetic fields. For each of the samples, the best fit of the experimental data of Delta chi/T, in the limit of weak magnetic fields in function of the reduced temperature, allowed us to obtain the values of As (diamagnetism of Schmidt) and BLD (LD parameter). The Lawrence-Doniach model (LD) has been used for the fluctuation analysis. It is demonstrated, by means of the analysis of the thermal fluctuations, that the YBa2Cu3-xFexO7-delta system has an excellent 2D scaling behavior (BLD).