Magnetization and microwave study of superconducting MgB2

Scientific paper - Original scientific paper

• Author: Antonije Dulčić
• Author: Dalibor Paar
• Author: Miroslav Požek
• Author: G. V. M. Williams
• Author: S. Kramer
• Author: C. U. Jung
• Author: Min-Seok Park
• Author: Sung-Ik Lee
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

We report magnetic-field-dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high-pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the dc irreversibility field exponent is ∼1.4. Microwave surface impedance measurements were carried out in applied magnetic fields up to 8 T. The low-field data show an absence of weak links in the superconducting state. By inverting the surface impedance data, we find a vortex depinning frequency that decreases with increasing magnetic field, which is characteristic of collective pinning.

• Keywords (english): critical-current density; upper critical-field; high-pressure; penetration depth; vortex dynamics; temperature; films; transport; frequency; cavity; microwave
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical review B: Condensed matter and materials physics
• Numbering: vol. 66, no. 1, pp. 014505-7
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.66.014505
• URN:NBN: urn:nbn:hr:217:152559
• Publication: 2002
• Document URL: http://link.aps.org/doi/10.1103/PhysRevB.66.014505
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2002) by the American Physical Society.
• Created on: 2019-10-13 12:06:30