The growth of Zn-doped YBCO single crystals

✍ Scribed by C.T. Lin; S.X. Li; A. Mackenzie; W. Zhou; P.D. Hunneyball; W.Y. Liang

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 1019 KB
• Volume: 193
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(92)90879-h

✦ Synopsis

Single crystals of YBa2Cu3_xZnxOT_j, (x_< 0.066) were obtained through long periodic step growth by adding ZnO to the primary phase region of the YBa2Ctl3OT_y phase on the YBa2Cu3OT_y-BaCu304 pseudo-binary line. The solubility of zinc in YBCO is found to be relatively low. The chemical composition (including oxygen ) has been accurately determined for all the Zn-doped YBCO crystals by EPMA. XRD showed that all the crystals were orthorhombic and the unit cell volume increased continuously with increasing zinc concentration. Crystals which had been annealed in oxygen showed a T, at 74, 72, 68 and 63 K for x=0.037, 0.042, 0.055 and 0.066, respectively. The primary phase was found to be located at the region having high fractions of BaCu304. In the course of the crystal growth study, several insulating compounds with approximate formulae YBaZn3_xCuxOy, Y2(Cu,Zn)xOy and (Y,Cu)BaZn2Oy were also found from the melt after solidification. The phase of YBaZn3_xCuxOj, was identified to be hexagonal with a,,, 5.0 A and c~ 9.5 A.