SUPERCONDUCTING PROPERTIES OF POLYCRYSTALLINE YBCO PREPARED BY A PYROLYTIC PROCESS

Polycrystalline YBCO was prepared by a pyrolytic process starting from citrate and tartrate precursors. The effect of the precursor on the s uperconducting properties was investigated by means of magnetic measur ements using a SQUID magnetometer, a Vibrating-Sample Magnetometer and an a.c. susceptometer. The critical temperature is not affected by th e type of precursor (T-c = 85 K for both). On the other hand, the prec ursor plays an important role on the critical current density, which i s found to be an order of magnitude higher in the sample obtained from citrates (J(c) (77 K, H = 0) = 2.3 . 10(4) A/cm(2) and 10(3) A/cm(2) for the from-citrate and from-tartrate sample, respectively).