A process for planarizing a substrate involves applying a coating of a first solution of yttrium oxide precursor to a rough substrate surface and heating to remove solvent and convert the yttrium oxide precursor to yttrium oxide. This is repeated with the first solution and then with the second solution. A final surface roughness less than 1 nm RMS may be obtained. In addition, a process for preparing a layered structure includes solution deposition planarization of a rough substrate using different concentrations of metal oxide precursor to provide a metal oxide surface having a surface roughness, and then depositing MgO by IBAD (ion beam assisted deposition). A benefit of a better in plane MgO texture was observed for lower molarities, and when two solutions of different concentrations was employed for coating the rough substrate prior to IBAD-MgO.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. DE-AC52-06NA25396 awarded by the U.S. Department of Energy. The government has certain rights in the invention.