Penetration depth λ(<i>T</i>) of YBa2Cu3O7−δ films determined from the kinetic inductance

Abstract

We examine the temperature dependence of the magnetic penetration depth λ(T) of YBa2Cu3O7−δ, determined from the kinetic inductance of a film patterned into a long meander line. This technique has sufficient sensitivity to study λ(T) to lower temperatures than have been examined previously. A numerical model which includes both the magnetic and kinetic inductances of the samples extracts λ(T) from the measured voltage. In reasonable agreement with other measurements, λ(0)≊2100 Å is deduced from fitting λ(0)2/λ(T)2 to the function 1−(T/Tc)2 for T/Tc≥0.4. We find λ(T)/λ(0)−1 is proportional to (T/Tc)2 for 0.06 ≤T/Tc≤0.4.