New technique for measuring the microwave penetration depth in high-Tc superconducting thin films

Abstract

The ferromagnetic resonance (FMR) technique has been used to obtain the microwave (MW) penetration depth in high-temperature superconductor (HTSC) thin film. An FMR-signal-generating thin permalloy film was sandwiched in between of two YBa2Cu3O7 films to probe the MW field penetrating through the films. Below the superconducting transition temperature T-c the HTSC films started to screen the marker inside the sandwich. The low-temperature saturation value lambda(ab) similar or equal to 1250 Angstrom at 25 K has been deduced for our c-axis films from the temperature dependence of the FMR signal intensity below T-c. (C) 2000 Elsevier Science B.V. All rights reserved.