| Autor: |
V. S. Flis, V.L. Svetchnikov, V.M. Pan, A. L. Kasatkin, A.A. Kalenyuk, V O Moskaliuk, A.I. Rebikov, C.G. Tretiatchenko |
| Rok vydání: |
2010 |
| Předmět: |
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| Zdroj: |
Journal of Physics: Conference Series. 234:012041 |
| ISSN: |
1742-6596 |
| Popis: |
We have carried out a comprehensive study of a relation between the nanostructure and electromagnetic properties of the films prepared by pulse laser deposition on LaAlO3 substrates using YBCO targets with BaZrO3 additives. HREM studies revealed that depending on the deposition conditions BZO can precipitate as nanorods normal to the substrate or as BaYZrxOy nano-pancakes. BZO nanorods are formed at lower laser power and higher substrate temperature. Their lattice is rotated by 3-4° to provide matching with matrix without dislocations. In a contrary, the nano-pancakes are surrounded with a great number of dislocations. Mechanisms of the nanostructure formation have been analyzed. Embedding of a proper kind of nanoparticles into HTS films leads not only to a certain increase of the critical current density Jc but to a substantial weakening of its field and thickness dependences compared with pure YBCO films. Negative curvature of I-V-curves (in double-log scale) for YBCO (BZO) films is an evidence of strong pinning on extended defects, such as nanorods and threading dislocations, and/or collective vortex pinning. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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