Observation of vortex structure in MgB$_2$ single crystals by Bitter decoration technique

Vinnikov, L. Ya.; Karpinski, J.; Kazakov, S. M.; Jun, J.; Anderegg, J.; Bud'ko, S. L.; Canfield, P. C.

Observation of vortex structure in MgB$_2$ single crystals by Bitter decoration technique

Authors

Description

We report the observation of superconducting vortices in pure and lightly Al doped MgB$_2$ single crystals. Low field experiments allow for the estimation of the London penetration depth, lambda ~ 1900 $Å$ for T$\sim$6 K. Experiments in higher fields (e.g. 200 Oe) clearly show a triangular vortex lattice in both real space (13 $μ$m by 13 $μ$m Bitter decoration image of over 1000 vortices) and reciprocal space.