Influence of cation modification on the environmental degradation of high temperature superconducting Y-Ba-Cu-O films

The corrosion resistance of high temperature superconducting (HTSC) Y-Ba-Cu-O (YBCO) films and doped YBCO films (lanthanum La, calcium Ca, silver Ag) was studied and their lifetimes in saturated steam environment at 75 and 23 °C were determined. The results indicate an enhancement of stability against environmental degradation for the films with increasing La content. We suppose that this enhancement is attributed to poor water solubility of lanthanum hydroxide protective films, which were formed in the first step of corrosion.