Thermally activated flux-flow in epitaxially grown YBa2(Cu1−χZnχ)3O7− thin films

✍ Scribed by C. Tomé-Rosa; G. Jakob; M. Paulson; P. Wagner; A. Walkenhorst; M. Schmitt; H. Adrian

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 193 KB
• Volume: 185-189
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(91)91212-m

✦ Synopsis

The influence of Zn-impurity atoms on the superconducting critical temperature T~, the resistive transitions in magnetic fields 0=~(B, T) and the critical current density j~b(B, T) of epitaxially grown, c-axis oriented YBa2(Cux_~Zn=)aO7 films is reported. For very small concentrations x < 0.005 we observe a narrowing of the resistive transitions which leads to a crossing of the depinning lines and corresponds to an enhancement of the average activation energy (U) by a factor of two. The pinning effectivity of the Zn-dopant atoms can also be deduced from an enhancement of j~b(B, T)/j~b(O, T) in large magnetic fields B > 6T and characteristic features in the angular dependence of j~b(B,T,~) where ~o is the angle between the external field/3 and the g-axis.