EFFECTS OF SNO2 ADDITIVES ON THE BENDABILITY AND SUPERCONDUCTIVITY OFYBCO SUPERCONDUCTORS

The influence of tin oxide additives on the diffusion bondability and superconductivity of YBa2Cu3O7-X ceramic was studied. The critical cur rent density Je and the critical temperature Te were tested by the sta ndard four-probe technique. in order co study the behavior and thermal properties of SnO2 additives in the YBa2Cu3O7-X superconductors in si ntering processes, the phase structure of YBa2Cu3O7-X powder with diff erent amount of SnO2 additives were investigated both by X-ray diffrac tion after sintering and by thermal analysis. The bonding strength of joints were measured by shearing test. The critical current density in creased with the SnO2 additives properly added. This improvement was c onsidered as the results of such phenomena as follows: (I)The density of specimen increased with the SnO2 additives increasing. (2) The Dinn ing force to magnetic flux was became larger due to the existence of t he additives. The shear strength of specimens increased with the SnO2 additives increasing. It was feasible to bond the YBCO superconductors using the SnO2 as the additive. The diffusion bonding thermal cycle w ould not affect the crystal structure of the YBCO.