F. Hentsch, H. Seidel, et al.
Physica C: Superconductivity and its applications
We report on zero-field nuclear spin-lattice relaxation measurements of 139La in La1.8Sr0.2CuO4-δin the normal and the superconducting state. Below the superconducting transition temperature Tcthe relaxation rate behaves like 1/T1∼ exp [- Δ/kT] with activation energy Δ = 11.5 meV leading to a gap energy of 2Δ = 23 meV. With Tc= 38 K the ratio 2Δ/kTc= 7.1 is obtained, which is twice as large as the weak-coupling value of 3.5. © 1988 IOP Publishing Ltd.
F. Hentsch, H. Seidel, et al.
Physica C: Superconductivity and its applications
H. Seidel, M. Mehring, et al.
The Journal of Chemical Physics
H. Seidel, M. Mehring, et al.
The Journal of Chemical Physics
R.K. Kremer, E. Sigmund, et al.
Zeitschrift für Physik B Condensed Matter