Strong magnetic field dependence of critical current densities and vortex activation energies in an anisotropic clean MgB2 thin film. (February 2015)

• Record Type: Journal Article
• Authors: Kim, Jeehoon; Haberkorn, N.; Nazaretski, E.; Paula, R. de; Tan, Teng; Xi, X.X.; Tajima, T.; Movshovich, R.; Civale, L.
• Is Part Of: Solid state communications. Volume 204(2015)
• Page Start: 56
• Page End: 60
• Publication Date: 2015-02
• Subjects: A. Superconducting materials -- B. Films -- C. Magnetic penetration depth -- D. Vortex pinning; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2014.11.015
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We report the influence of two-band superconductivity on the flux creep and the critical current densities of a MgB2 thin film. The small magnetic penetration depth of λ =50±10 nm at T =4 K is related to a clean π-band. We find a high self-field critical current density J c, which is strongly reduced with applied magnetic field, and attribute this to suppression of the superconductivity in the π-band. The temperature dependence of the creep rate S ( T ) at low magnetic field can be explained by a simple Anderson–Kim mechanism. The system shows high pinning energies at low field that are strongly suppressed by high field.