Millimeter-wave surface resistance of laser-ablated YBa2Cu3O7−δ superconducting films

Abstract
We have measured the millimeter‐wave surface resistance of YBa2Cu3O7−δ superconducting films in a gold‐plated copper host cavity at 58.6 GHz between 25 and 300 K. High quality laser‐ablated films of 1.2 μm thickness were deposited on SrTiO3 and LaGaO3 substrates. Their transition temperatures (Tc’s) were 90.0 and 88.9 K, with a surface resistance at 70 K of 82 and 116 mΩ, respectively. These values are better than the values for the gold‐plated cavity at the same temperature and frequency.