CaNdAlO4 perovskite substrate for microwave and far-infrared applications of epitaxial high T c superconducting thin films

Abstract
Single‐crystal perovskite calcium‐neodymium aluminate CaNdAlO4 has been grown and tested as a substrate material for high Tc superconducting thin films. The material is chemically stable, can be fabricated into the form of large, twin‐free wafers, permits deposition of epitaxial Y‐Ba‐Cu‐O and Bi‐Sr‐Ca‐Cu‐O films, and exhibits low dielectric permittivity (ε≂20) and very low losses (tan δ≂103 at 100 K) at sub‐THz frequencies. Its high potential in microwave applications of thin‐film high Tc superconductors is clearly demonstrated.