Microstructure, resistivity and the anisotropy of the upper critical field in NbN thin films

D. A. Rudman, Jenh-Yih Juang

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

The upper critical field of most polycrystalline NbN thin films is anisotropic, with the perpendicular critical field Hc2(1) larger than the parallel critical field Hc2(11). We have measured the angular dependence Hc2(e) for samples with both a columnar and non-columnar microstructure In both cases we find a rounded maximum near Hc2(1). The shape of HC2 (e), combined with the known microstructure of the films and the linear temperature dependence of Hc2 for. both field orientations leads us to conclude that the mechanism responsible for this anisotropy is an anisotropic conductivity in the film, probably due to differences in the grain boundary resistance in the plane of the film and normal to the film. In contrast, a single crystal film shows only surface superconductivity.

Original languageEnglish
Pages (from-to)831-838
Number of pages8
JournalIEEE Transactions on Magnetics
Volume23
Issue number2
DOIs
StatePublished - 1 Jan 1987

Fingerprint Dive into the research topics of 'Microstructure, resistivity and the anisotropy of the upper critical field in NbN thin films'. Together they form a unique fingerprint.

Cite this