THE EFFECT OF THE INTERACTION BETWEEN THE FILMS AND THE SUBSTRATES ON THE MICROWAVE PROPERTIES Of YBCO THIN FILMS

Abstract

The microwave properties of YBa 2 Cu 3 O 7- x / LaAlO 3 (YBCO/LAO) and YBa 2 Cu 3 O 7- x / MgO (YBCO/MgO) thin films have been investigated by microstrip resonator technique. The penetration depth λ0(0 K ) and the microwave surface resistance Rs can be obtained by analyzing the experimental data of the temperature dependence of resonant frequency, unload quality factor of the microstrip resonator. The stress in the two thin films can be obtained from their XRD patterns. The result shows that the stronger stress in YBCO/LAO thing film makes it have larger microwave surface resistance at lower temperature.