General solution for the complex frequency shift in microwave measurements of thin films

Scientific paper - Original scientific paper

• Author: D.-N. Peligrad
• Author: B. Nebendahl
• Author: M. Mehring
• Author: Antonije Dulčić
• Author: Miroslav Požek
• Author: Dalibor Paar
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Perturbation of a microwave cavity by a small sample with variable dielectric, magnetic, or conducting properties is considered. The complex frequency shift is derived in terms of a volume integral, or equivalently, in terms of a surface integral. These are used to obtain a general formula for thin films in the microwave electric field maximum. The complex frequency shift depends on the depolarization factor of the film and on its thickness in a nontrivial way. The previously known expressions for the complex frequency shift are shown to be good approximations of the present solution in the low and high conductivity limits. Our formula is applied to calculate the signal shapes in superconducting films of various geometric parameters and conductivities. It is shown that a diversity of signal shapes can result, and experimental support of those shapes is provided. The role of the dielectric substrate on which the thin film is grown is simply reduced to an asymmetry effect.

• Keywords (english): superconducting thin films; microwave measurement; surface conductivity; high-frequency effects
• 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. 64, no. 22, pp. 224504-12
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.64.224504
• URN:NBN: urn:nbn:hr:217:219108
• Publication: 2001
• Document URL: http://link.aps.org/doi/10.1103/PhysRevB.64.224504
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2001) by the American Physical Society.
• Created on: 2019-10-11 15:31:31