Theory of the upper critical field in antiferromagnetic superconductors

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.29.6155· OSTI ID:6949274

Ro, C; Levin, K

We compute the temperature T dependence of the upper critical field H/sub c/2(T) in antiferromagnetic (AF) superconductors. Using a strong-coupling formalism we explicitly treat the effects of the molecular field H/sub Q/, inelastic and elastic spin-fluctuation scattering and magnetic as well as nonmagnetic impurities. A sum rule is used to relate the T dependence of H/sub Q/ to that of the spin-fluctuation scattering. The decreased pair breaking observed below the Neel temperature in SmRh/sub 4/B/sub 4/ and the increased pair breaking seen in the AF Chevrel compounds will both occur in our theory for a reasonable choice of parameters. For larger values of the dimensionless spin-exchange coupling constant N(0)J/sup c/f, spin-fluctuation-scattering effects dominate over those of H/sub Q/ and decreased pair breaking is observed below T/sub N/. For smaller values of the coupling constant, the converse is true. Impurity scattering is treated in a self-consistent fashion. As a consequence, the molecular field H/sub Q/ is altered by nonmagnetic impurities. This leads to important pair-breaking effects in H/sub c/2. A physical manifestation of this pair breaking is a qualitative change in the shape of the H/sub c/2 versus T curve, as nonmagnetic impurities are added. We give detailed predictions for the expected effects of these impurities on H/sub c/2 which can be tested experimentally.

• Research Organization: Department of Physics and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637
• OSTI ID: 6949274
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 29:11; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
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& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
ANTIFERROMAGNETIC MATERIALS
CRITICAL FIELD
DATA
ELASTIC SCATTERING
EQUATIONS
FLUCTUATIONS
IMPURITIES
INELASTIC SCATTERING
INFORMATION
MAGNETIC FIELDS
MAGNETIC MATERIALS
MATERIALS
MATHEMATICAL MODELS
NUMERICAL DATA
PARTICLE MODELS
PARTICLE PROPERTIES
SCATTERING
SELF-CONSISTENT FIELD
SPIN
STRONG-COUPLING MODEL
SUM RULES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THEORETICAL DATA
TYPE-II SUPERCONDUCTORS
VARIATIONS