Effect of mixed vanlence impurities on superconductivity

Journal Article · Thu Apr 01 04:00:00 EST 1982 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00682018· OSTI ID:5497562

Schlottmann, P

The phase transition temperture T/sub c/, the specific heat discontinuity ..delta..C, and the critical magnetic field of a superconductor containing intermediate valence impurities are calculated. The impurities are described by the Anderson model with orbital degeneracy in the U..-->..infinity limit when two active ionic configurations, corresponding to 4f/sup 0/ and 4f/sup 1/ (Ce impurities), are present. The properties of the superconducting alloy are expressed in terms of the t-matrix for the scattering off the impurities exists. The transition temperature decreases approximately exponentially with the impurity concentration as for the spin-fluctuation limit and the strong coupling Kondo limit. The critical field deviation function D(T/T/sub c/) is the same as for the BCS theory. This indicates pair weakening rather than pair breaking, which is consistent with the picture that the mixed valence problem is driven by charge fluctuations, while spin fluctuations play only a secondary role.

• Research Organization: Institute fuer Theoretische Physik, Freie Universitaet Berlin, Berlin, Germany
• OSTI ID: 5497562
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 47:1; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL FIELD
FLUCTUATIONS
FUNCTIONS
GREEN FUNCTION
IMPURITIES
MAGNETIC FIELDS
MATRICES
ORDER PARAMETERS
PHYSICAL PROPERTIES
S MATRIX
SPECIFIC HEAT
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
VALENCE
VARIATIONS