In this paper, a study of the effect of Al substitution on the upper critical field, B_c2, in Al_xMg_(1−x)B_2 samples is presented. We find a straightforward correlation between B_c2 and the sigma-band gap, Delta_sigma, evaluated by point-contact measurements. Up to x=0.2, B_c2 can be well described within a clean limit model and its decrease with x is directly related to the suppression of Delta_sigma.
|Titolo:||Critical field of Al-doped MgB2 samples: Correlation with the suppression of the sigma-band gap|
|Data di pubblicazione:||2005|
|Digital Object Identifier (DOI):||10.1103/PhysRevB.71.144505|
|Appare nelle tipologie:||1.1 Articolo in rivista|