ISSN:
1090-6509
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The real part R s and the imaginary part X s of the surface impedance Z s=R s+ iX s of Tl2Ba2CaCu2O8−δ and YBa2Cu3O6.95 single crystals have been measured with high precision at frequency ω/2π=9.4 GHz in the temperature range 0〈T〈140 K. In the Tl2Ba2CaCu2O8−δ crystal a linear temperature dependence R s(T) has been found for T⩽50 K, and the magnetic field penetration depth λ(4.2 K)=X s(4.2 K)/ω μ 0≈3760 Å has been measured. Along with well known features of the function Z s(T) in high-quality YBa2Cu3O6.95 single crystals, such as the linearity of λ(T) and R s(T) for T〈T c/3 and a maximum of R s(T) at T∼T c/2, the linearity range of λ(T) extends to T≃50 K, and this curve has a plateau in the range 60〈T〈85 K. The curve of R s(T) in both the superconducting and normal states of YBa2Cu3O6.95 is well described by a two-fluid model with the electron-phonon mechanism of quasiparticle relaxation. A formula describing the curve of λ 2(0)/λ 2(T) throughout the studied temperature range is also given.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1134/1.558395