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Title: Upper critical fields of periodic and quasiperiodic Nb-Ta superlattices

Abstract

Upper critical fields have been studied for two series of Nb-Ta superlattices grown by molecular-beam epitaxy with both periodic and quasiperiodic (Fibonacci sequence) layering. X-ray results are presented to characterize the nature and quality of the layering. Positive curvature in the perpendicular upper critical field (H/sub c//sub 2//sub perpendicular/), pronounced negative curvature near T/sub c/ in the parallel upper critical field (H/sub c//sub 2//sub X/), and dimensional crossover are observed in both types of samples. For quasiperiodic samples two upturns are observed in H/sub c//sub 2//sub X/ with decreasing temperature. These are shown to be associated with dimensional crossover occurring twice as the superconducting coherence length in the growth direction, xi/sub perpendicular/, samples the two length scales, 2d/sub Nb/ and d/sub Nb/, that are present in these structures.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Department of Physics, The University of Michigan, Ann Arbor, Michigan 48109
OSTI Identifier:
6881446
Resource Type:
Journal Article
Journal Name:
Phys. Rev. B: Condens. Matter; (United States)
Additional Journal Information:
Journal Volume: 38:4
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; NIOBIUM; CRITICAL FIELD; SUPERCONDUCTIVITY; TANTALUM; MOLECULAR BEAM EPITAXY; MONOCRYSTALS; PROXIMITY EFFECT; SAPPHIRE; SUBSTRATES; SUPERLATTICES; TEMPERATURE DEPENDENCE; TYPE-II SUPERCONDUCTORS; ULTRAHIGH VACUUM; X-RAY DIFFRACTION; ALUMINIUM COMPOUNDS; ALUMINIUM OXIDES; CHALCOGENIDES; COHERENT SCATTERING; CORUNDUM; CRYSTALS; DIFFRACTION; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELEMENTS; EPITAXY; MAGNETIC FIELDS; METALS; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SCATTERING; SUPERCONDUCTORS; TRANSITION ELEMENTS; 360104* - Metals & Alloys- Physical Properties; 656100 - Condensed Matter Physics- Superconductivity

Citation Formats

Cohn, J L, Lin, J J, Lamelas, F J, He, H, Clarke, R, and Uher, C. Upper critical fields of periodic and quasiperiodic Nb-Ta superlattices. United States: N. p., 1988. Web. doi:10.1103/PhysRevB.38.2326.
Cohn, J L, Lin, J J, Lamelas, F J, He, H, Clarke, R, & Uher, C. Upper critical fields of periodic and quasiperiodic Nb-Ta superlattices. United States. https://doi.org/10.1103/PhysRevB.38.2326
Cohn, J L, Lin, J J, Lamelas, F J, He, H, Clarke, R, and Uher, C. 1988. "Upper critical fields of periodic and quasiperiodic Nb-Ta superlattices". United States. https://doi.org/10.1103/PhysRevB.38.2326.
@article{osti_6881446,
title = {Upper critical fields of periodic and quasiperiodic Nb-Ta superlattices},
author = {Cohn, J L and Lin, J J and Lamelas, F J and He, H and Clarke, R and Uher, C},
abstractNote = {Upper critical fields have been studied for two series of Nb-Ta superlattices grown by molecular-beam epitaxy with both periodic and quasiperiodic (Fibonacci sequence) layering. X-ray results are presented to characterize the nature and quality of the layering. Positive curvature in the perpendicular upper critical field (H/sub c//sub 2//sub perpendicular/), pronounced negative curvature near T/sub c/ in the parallel upper critical field (H/sub c//sub 2//sub X/), and dimensional crossover are observed in both types of samples. For quasiperiodic samples two upturns are observed in H/sub c//sub 2//sub X/ with decreasing temperature. These are shown to be associated with dimensional crossover occurring twice as the superconducting coherence length in the growth direction, xi/sub perpendicular/, samples the two length scales, 2d/sub Nb/ and d/sub Nb/, that are present in these structures.},
doi = {10.1103/PhysRevB.38.2326},
url = {https://www.osti.gov/biblio/6881446}, journal = {Phys. Rev. B: Condens. Matter; (United States)},
number = ,
volume = 38:4,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 1988},
month = {Mon Aug 01 00:00:00 EDT 1988}
}