Application of proximity effect theory to metallic multilayers

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:82846

Koperdraad, R T.W.; Lodder, A ^[1]

---

1. Free Univ., Amsterdam (Netherlands). Faculty of Physics and Astronomy

The Takahashi-Tachiki equations, describing the critical properties of proximity effect systems in the dirty limit, are solved exactly using the full eigenfunction expansion. Both parallel and perpendicular critical fields are calculated. The theory is applied to experimental data of Kanoda et al. for V/Ag and of Chun et al. for Nb/Cu, using the {Tc} of the superconducting material and the diffusion coefficients of both materials as fit parameters. For the 3D systems the fits compare nicely with the experimental results, but for 2D systems this is not always the case. It is found that the V and Nb critical temperatures necessary to fit the data can be larger than the corresponding bulk critical temperatures. This contrasts with what has been observed for single V and Nb films. Additionally, the diffusion coefficients resulting from the fit procedure are found to be much smaller than one would expect from resistivity measurements. In the light of these anomalies earlier less complete calculations are reconsidered. It turns out that several assertions are superficial and cannot be affirmed by the results of the present work.

• OSTI ID: 82846
• Report Number(s): CONF-940142--; ISBN 0-8194-1452-2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
COPPER
CRITICAL FIELD
LAYERS
NIOBIUM
PROXIMITY EFFECT
SILVER
SUPERCONDUCTIVITY
SUPERLATTICES
THEORETICAL DATA
TRANSITION TEMPERATURE
VANADIUM