NMR and spin-lattice relaxation rate of89Y,63Cu in radiation disordered YBa2Cu3O6.9

Verkhovskiǐ, S. V.; Zhdanov, Yu. I.; Bogdanovitch, A. M.; Mikhalyov, K.N.; Aleksashin, B. A.; Serikov, V. V.; Lavrentjev, V.V.; Sadovskiǐ, M. V.

doi:10.1007/bf03166287

Cited by 4 publications

(2 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…258,259 . The study of NMR relaxation rate on 89 Y nuclei in radiationally disordered Y Ba 2 Cu 3 O 6.95 (which opposite to Cu nuclei demonstrate Korringa behavior) 260,261 has shown the anomalies (a maximum in the so called Warren's enhancement factor) which according to Ref.…”

Section: B High-t C Superconductorsmentioning

confidence: 97%

Superconductivity and localization

1997

View full text Add to dashboard Cite

We present a review of theoretical and experimental works on the problem of mutual interplay of Anderson localization and superconductivity in strongly disordered systems. Superconductivity exists close to the metalinsulator transition in some disordered systems such as amorphous metals, superconducting compounds disordered by fast neutron irradiation etc. Hightemperature superconductors are especially interesting from this point of view. Only bulk systems are considered in this review. The superconductor-insulator transition in purely two-dimensional disordered systems is not discussed.We start with brief discussion of modern aspects of localization theory including the basic concept of scaling, self-consistent theory and interaction effects. After that we analyze disorder effects on Cooper pairing and superconducting transition temperature as well as Ginzburg-Landau equations for superconductors which are close to the Anderson transition. A necessary generalization of usual theory of "dirty" superconductors is formulated which allows to analyze anomalies of the main superconducting properties close to disorder-induced metal-insulator transition. Under very rigid conditions superconductivity may persist even in the localized phase (Anderson insulator).Strong disordering leads to considerable reduction of superconducting transition temperature T c and to important anomalies in the behavior of the upper critical field H c2 . Fluctuation effects are also discussed. In the vicinity of Anderson transition inhomogeneous superconductivity appears due to statistical fluctuations of the local density of states.We briefly discuss a number of experiments demonstrating superconductivity close to the Anderson transition both in traditional and high-T c superconductors. In traditional systems superconductivity is in most cases destroyed before metal-insulator transition. In case of high-T c superconductors a number of anomalies show that superconductivity is apparently conserved in the localized phase before it is suppressed by strong enough disorder. The concept of electron localization 1 is basic for the understanding of electron properties of disordered systems 2,3 . In recent years a number of review papers had appeared, extensively discussing this problem [4][5][6][7] . According to this concept introduction of sufficiently strong disorder into a metallic system leads to spatial localization of electronic states near the Fermi level and thus to a transition to dielectric state (Anderson transition). After this transition dc conductivity (at zero temperature, T = 0) vanishes, despite the finite value of electronic density of states at the Fermi level (at least in one-electron approximation).At the same time it is well-known that even the smallest attraction of electrons close to the Fermi level leads to formation of Cooper pairs and the system becomes superconducting at sufficiently low temperatures 8,9 . It is known that the introduction of disorder which does not break the time-reversal invariance (normal, nonm...

show abstract

Section: B High-t C Superconductorsmentioning

confidence: 97%

Superconductivity and localization

1997

View full text Add to dashboard Cite

show abstract

“…I will not deal with structural modifications by irradiation. Verkhovskii et al [20] instead give a thorough account on these aspects in this volume. Nor will I treat the early investigations of the phase diagram of La2_xSrxCuO 4 by NQR [21,22].…”

Section: Introductionmentioning

confidence: 99%

What does NMR tell us about the electronic state of high-T c superconductors?

Mehring

1992

Appl. Magn. Reson.

View full text Add to dashboard Cite

An introduction to the models which are usually applied, when interpreting the NMR (nuclear magnetic resonance) parameter Knight shift (Ks) and spin-lattice relaxation rate 1/T~ in the normal and the superconducting state of high-temperature superconductors, is given. The different hyperfine interaction parameters involved, as well as the static and dynamic susceptibility z(q,o)) will be discussed. I will point at those highlights as antiferromagnetic correlations, spin gap and vortex lattice dynamics which have emerged from the analysis of the NMR data.

show abstract

NMR and spin-lattice relaxation rate of89Y,63Cu in radiation disordered YBa2Cu3O6.9

Cited by 4 publications

References 14 publications

Superconductivity and localization

Superconductivity and localization

What does NMR tell us about the electronic state of high-T c superconductors?

Electron-spin-lattice relaxation inGdBa2Cu3
Ацаркин
¹
,
Демидов
²
,
Vasneva
³

1995
Phys. Rev. B
38
2
47
0
View full text Add to dashboard Cite

Contact Info

Product

Resources

About

NMR and spin-lattice relaxation rate of89Y,63Cu in radiation disordered YBa2Cu3O6.9

Cited by 4 publications

References 14 publications

Superconductivity and localization

Superconductivity and localization

What does NMR tell us about the electronic state of high-T c superconductors?

Electron-spin-lattice relaxation inGdBa2Cu3Ацаркин1, Демидов2, Vasneva3 1995Phys. Rev. B382470View full textAdd to dashboardCite

Contact Info

Product

Resources

About

Electron-spin-lattice relaxation inGdBa2Cu3
Ацаркин
¹
,
Демидов
²
,
Vasneva
³

1995
Phys. Rev. B
38
2
47
0
View full text Add to dashboard Cite