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Critical Field of MGB2 : Crossover from Clean to Dirty Regimes

M. Putti·V. Braccini·C. Ferdeghini·I. Pallecchi·A. S. Siri·F. Gatti·P. Manfrinetti·A. Palenzona
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Abstract

We have studied the upper critical field, Bc2, in poly-crystalline MgB2 samples in which disorder was varied in a controlled way to carry selectively p and s bands from clean to dirty limit. We have found that the clean regime survives when p bands are dirty and s bands are midway between clean and dirty. In this framework we can explain the anomalous behaviour of Al doped samples, in which Bc2 decreases as doping increases.

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M. Putti, V. Braccini, C. Ferdeghini, I. Pallecchi, A. S. Siri, F. Gatti, P. Manfrinetti, A. Palenzona. 2003-10-20. Critical Field of MGB2 : Crossover from Clean to Dirty Regimes. https://doi.org/10.1103/physrevb.70.052509

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