Influence of Al doping on the critical fields and gap values in magnesium diboride single crystals

T. Klein, L. Lyard, J. Marcus +9

The lower ($H_{c1}$) and upper ($H_{c2}$) critical fields of Mg${}_{1-x}$Al${}_x$B${}_2$ single crystals (for $x=0$, 0.1 and $\gtrsim 0.2$) have been deduced from specific heat and l…