Microwave Measurements of Surface Resistance and Complex Conductivity of NdBaCuO Films

Abstract

Typically microwave properties of High Temperature Superconducting films are defined in terms of surface resistance Rs computed from Q-factor measurements obtained using one of resonant techniques. While NdBaCuO films are known to have higher TC and JC than YBaCuO films, not much is known about their loss at high frequencies. In this paper we report on microwave properties of NdBaCuO films of varying quality and thickness based on measurements with a 25GHz sapphire Hakki Coleman resonator and computations using two approaches: the surface resistance and the complex conductivity as primary variables for rigorous electromagnetic solutions.