Metalorganic chemical vapor deposition route to epitaxial neodymium gallate thin films

Phase-pure epitaxial thin films of the YBa₂Cu₃O _7-δ lattice-matched, low dielectric loss perovskite insulator NdGaO₃ have been grown on (110) LaAlO₃ substrates by a metalorganic chemical vapor deposition (MOCVD)/post-annealing process. Amorphous Nd-Ga-O films are first prepared by MOCVD using the volatile metalorganic β-diketonate precursors Nd(dpm)₃ and Ga(dpm)₃ (dpm=dipivaloylmethanate). Subsequent postannealing affords phase pure, highly oriented [(001) and/or (110) orientations perpendicular to the substrate surface] and epitaxial NdGaO₃ films as assessed by x-ray diffraction θ-2θ, ω, and φ scans. Cross-sectional high-resolution electron microscopic images show that the epitaxial growth occurs with atomically abrupt film-substrate interfaces and with coexisting NdGaO ₃ (001) and (110) orientation domains.