Europhys. Lett.
Volume 64, Number 3, November 2003
Page(s) 399 - 405
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00105-4
Europhys. Lett., 64 (3) , pp. 399-405 (2003)

Scattering approach to the magnetic susceptibility of high-temperature superconductors

Z. Janu1, 2 and G. M. Tsoi1

1  Institute of Physics, ASCR - Na Slovance 2, 182 21 Prague 8, Czech Republic
2  Faculty of Mathematics and Physics, Charles University V Holesovickách 2, 180 00 Prague 8, Czech Republic

(Received 7 May 2003; accepted in final form 18 August 2003)

We study the dc and ac magnetic susceptibility of high-temperature superconductors in weak magnetic fields. The high-resolution magnetic measurements were done using the non-commercial SQUID magnetometer with the sample in a properly quiet electromagnetic surrounding. The sample is in a residual external ac field smaller than 1 $\un{nT}$ and the typical applied ac field is about 1 $\un{\mu T}$. We show that the interpretation of the temperature dependence of the susceptibility measured under these conditions cannot be based on temperature-dependent suprefluid density, but can be interpreted as due to temperature-dependent electron scattering.

74.25.Ha - Properties of type I and type II superconductors: Magnetic properties.
74.25.Fy - Transport properties (electric and thermal conductivity, thermoelectric effects, etc.).

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