Depression of the superconducting transition temperature by magnetic impurities: Effect of Kondo resonance in the f density of states

N. E. Bickers; G. E. Zwicknagl

doi:10.1103/PhysRevB.36.6746

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Depression of the superconducting transition temperature by magnetic impurities: Effect of Kondo resonance in the f density of states

N. E. Bickers, G. E. Zwicknagl

DOI 10.1103/PhysRevB.36.6746 · Physical Review B

T1

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Abstract

A new formulation is presented for the calculation of superconducting Tc depression by dilute Ce impurities. The treatment is based on the finite-temperature large-degeneracy expansion for the degenerate-orbital Anderson model. The results may be simply interpreted in terms of resonant structure in the one- and two-body scattering amplitudes; the resonance scale, T0, may, in principle, be measured directly by inverse-photoemission studies of the f density of states. The initial slope of the depression curve (-dTc/dC)‖C=0 depends solely on the ratio T0/Tc0, with Tc0 the pure-metal transition temperature. The maximum initial slope is anomalously large in comparison with typical values for nonresonant magnetic impurity scattering. For an orbital degeneracy N=6, maximal depression occurs for T0≃5Tc0. .AE

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
(La,Ce)B6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown