Effects of PbO and BaPbO_3 Additives on the Properties of YBa_2Cu_3O_x

摘要

The superconducting properties of YBa_2Cu_3O_x with different content impurities of PbO and BaPbO_3 were studied. When the PbO was used as an additive in YBa_2Cu_3O_x, although the melting point could be reduced, the superconductivity became poor. From the XRD pattern of the sintered mixture of YBa_2Cu_3O_x and PbO it was known that there is a reaction between YBa_2Cu_3O_x and PbO, and the product is BaPbO_3. In the process of the reaction the superconducting phase of YBa_2Cu_3O_x was decreased and BaPbO_3 would be the main pha se in the sample. Therefore, BaPbO_3 was chosen as the impurity additive for the comparative study. The sin gle phase of BaPbO_3 was synthesized by the simple way from both mixtures of BaCO_3 and PbO, BaCO_3 an d PbO_2. Different contents of BaPbO_3 (10%, 20%, 30%) were added in the YBa_2Cu_3O_x. By the phase analys is in the XRD patterns it was proved that there was no reaction between YBa_2Cu_3O_x and BaPbO_3. When Ba PbO_3 was used as impurity in YBa_2Cu_3O_x the superconductivity was much better than PbO as an impurity a dditive in YBa_2Cu_3O_x.