A new method of YBa2Cu3O7−x single-crystal growth in Al2O3 crucibles with layered protective covers

✍ Scribed by T.E. Os'kina; D. Wehler; H. Piel; R. Röth; Yu.D. Tretyakov

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 362 KB
• Volume: 242
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)02399-9

✦ Synopsis

A new method ofYBa2Cu3OT_x (YBCO) crystal growth is presented, which uses A1203 crucibles with protective covers. The protective cover includes at least two ceramic layers, which are composed of (Y203 + Y2BafuOs) mixtures sintered under proper conditions. The layer nearest to the A1203 crucible wall is enriched by Y203 and protects the crystallization zone against AI pollution. The layer nearest to the Y-Ba-Cu-O melt consists of a pure Y2BaCuOs phase and provides the introduction of Y into the reaction volume via partial dissolution. Large crystals of 3.2 × 3.2×0.2 mm 3 of high purity with low residual microwave losses have been grown by this technique from YBazCu3OT_x+Ba2.sCUT.2Ox flux. This method can be extended for other single crystals and melted material. The protective covers may be prepared also on crucibles of other materials, if they have a good thermal stability and can hold several thermal cycles.