Substrate materials for oxide superconductors

The invention provides an improved substrate for growing layers of oxide superconductor materials for us in high current engineering applications. The invention also provides superconducting laminates based on the inventive substrates, and processes of r the manufacture thereof. The substrate materials comprise an alloy layer consisting essentially of either (a) a cube-texture FeNi alloy in the composition range 47% Ni to 58% Ni, or (b) a cube-texture Ni-Cu alloy in the composition range 41% Ni to 44% Ni. Preferably, the substrate further comprises an oxide buffer layer covering a surface of the alloy layer.