Effects of structural and transport properties of YBa2Cu3-xAlxO7-Compound

Samples of YBa2Cu3-xAlxO7- with x=0, 0.01, 0.02, 0.03 and 0.045 are prepared by 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. R-T measurements show a small decrease of TC (zero) with increasing Al doping up to x=0.02, and followed by a faster decrease with increasing doping concentration. We suggest that substitution of Al at Cu(1) site, makes holes localized at Cu-O chains and decreases TC. The crystal structure of YBa2Cu3-xAlxO7- is refined by the MAUD analysis. The orthorhombicity decreases with increasing Al doping. The Critical current density increases with increasing Al doping up to x=0.02 and then decreases.