Microwave study of magnetic field penetration parallel to thin niobium films

• Published in: Physica. C, Superconductivity Vol. 460; no. 2; pp. 1293 - 1294
• Main Authors: Grbić, M.S., Janjušević, D., Požek, M., Dulčić, A., Wagner, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2007; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Low tc films; Microwave response; Mixed state; Parallel field; Physics; Superconducting films and low-dimensional structures; Superconductivity; Thin film; 74.25.Qt; Microwave response; Parallel field; Mixed state; 74.25.Op; 74.40.+k; 74.25.Nf; 74.78.Db; Thin film; Superconducting thin films; Microwave radiation; Magnetic field effects; Order parameters; Niobium; 74.25.Qt Microwave response; Vortices; Size effect
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2007.03.415

Complex conductivity of high quality niobium thin films has been investigated by microwave technique in parallel static magnetic field. For the 40 nm thick film no vortices can be formed and the microwave penetration is defined by the strength of the superconducting order parameter which varies with the applied magnetic field. 160 nm thick measured film allows formation of two rows of vortices. Microwave dissipiation is dominated by dynamics of vortices which is strongly affected by size effects. Results have been compared with the generalised models of complex conductivity for low-dimensional superconductor in mixed state following earlier considerations by other authors.