Quantum dimensional effect in powders of the high-Tc superconductor YBa2Cu3O7-δ

✍ Scribed by V. Fleisher; E. Lähderanta; R. Laiho; Yu.P. Stepanov

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 338 KB
• Volume: 170
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(90)90242-7

✦ Synopsis

Low-field magnetization has been investigated in powders of YBa2Cu3OT_~ using ~amples with different maximal characteristic particle sizes dm~ of between 2.4 and 7.4 ~m. Measurements of the thermoremanent magnetization reveal the existence of a threshold field H~ corresponding to trapping of a single flux quantum ¢~0 in microscrystal: H~ = ( 1.1 _+ 0.2) ~o/d2m~. Flux creep was found to depend on the grain size, giving evidence for the presence of a surface barrier of flux trapping. A reversible temperature dependence of the thermoremanent magnetization has been observed. This effect is attributed to a local field created by particles containing trapped flux.