Study on YbBaCuO superconductor of Yb2O3–BaCO3–CuO system

The preparation of YbBaCuO superconductor was investigated due to its lower melting point than YBaCuO. DTA measurement showed that the melting point of YbBa2Cu3Ox was about 980 C, which was 30 C lower than that of YBa2Cu3Ox compound. But the liquid phase appeared at 910 C, meaning YbBa2Cu3Ox began to decompose below 980 C. Therefore, solid state sintering process of YbBa2Cu3Ox should take place below 910 C. The SmBaCuO crystals were used as seeds to introduce the large YbBaCuO crystal growth. In the melt-condensed process, the heating temperature was reduced from 980 to 900 C during 40 h, in that period the textured YbBaCuO was well-grown. The structure of textured YbBaCuO was observed with SEM and XRD, and the zero resistance superconductivity and the Jc of textured YbBaCuO were at 86 K and 770 A/cm2 (77 K, 0 H), resp. 12 refs.