Electronic anisotropy, magnetic field-temperature phase diagram and their dependence on resistivity inc-axis oriented MgB2thin films
- 2 May 2001
- journal article
- Published by IOP Publishing in Superconductor Science and Technology
- Vol. 14 (6) , 315-319
- https://doi.org/10.1088/0953-2048/14/6/304
Abstract
An important predicted, but so far uncharacterized, property of the new superconductor MgB2 is electronic anisotropy arising from its layered crystal structure. Here we report on three c-axis oriented thin films, showing that the upper critical field anisotropy ratio Hc2∥/Hc2⊥ is 1.8 to 2.0, the ratio increasing with higher resistivity. Measurements of the magnetic field-temperature phase diagram show that flux pinning disappears at H*≈0.8Hc2⊥(T) in untextured samples. Hc2∥(0) is strongly enhanced by alloying to 39 T for the highest resistivity film, more than twice that seen in bulk samples.Keywords
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