Patent ID: 8633138

Claim:
A method of depositing a buffer layer of epitaxial metal oxide on a textured metal substrate, said method comprising the steps of: (a) depositing on a textured metal substrate a layer of a precursor of an oxide of the formula A 2−x B 2+ xO 7 where A is a metal of valence 3, B is a metal of valence 4, and x is a number between −0.1 and +0.1, wherein the metals are deposited from a carboxylate solution of said metals A and B maintained at a temperature of between 20° C. and 40° C., the solution having a viscosity, measured at the temperature of the solution, of between 1 mPa s and 20 mPa s; (b) drying said layer of oxide precursor on the metal substrate at a temperature of between 60° C. and 150° C.; (c) heating the dried metal substrate to a temperature sufficient to pyrolyse the oxide precursor to form the metal oxide, at least part of said heating being carried out under a flow of reducing gas having a flow rate greater than 0.005 cm/s.