2002/09/15 by M. R. Eskildsen, M. Kugler, G. Levy +9 · 1 citation
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1016/s0921-4534(02)02301-8
published as Physica C, vol. 385, pp. 169-176 (2003) · 12 pages, 7 figs. Submitted to Physica C
arxiv created 2002/09/15 · openalex publication_date 2003/01/21 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report on the results of scanning tunneling spectroscopy measurements on single crystals of Mg2. Tunneling was performed both parallel and perpendicular to the crystalline c-axis. In the first case, a single superconducting gap (Deltapi = 2.2 meV) associated with the pi-band is observed. Tunneling parallel to the ab-plane reveals an additional, larger gap (Deltasigma ~ 7 meV) originating in the highly two-dimensional sigma-band. Vortex imaging in the pi-band was performed with the field and tunnel current parallel to the c-axis. The vortices have a large core size compared to estimates based on Hc2, and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. A comparison to specific heat measurements is performed.