We investigate the structure and morphology of thin overlayers of MgO on lattice-matched interlayers of Cr0.7Mo0.3 grown on MgO(001) substrates. Lattice matching results is unstrained MgO epitaxial films with short- and long-range structual order of comparable quality to those of buffer layers of MhO grown on MgO(001) under optimized step-flow growth conditions. In addition, the structural coherence of the oxide/metal interface is excellent due to lattice matching, in contrast to lattice-mismatched systems. However, MgO does not grow in a perfectly laminar fashion on Cr0.7M0.3 due to surface and interace free-energy imbalances; thin MgO films exhibit mean roughnesses of ~4 A with terrace widths of several hundred A. Nevertheless, the use of lattice-matched conducting interlayers between a bulk oxide substrate and an epitaxial thin film on the same material allows high-quality insulting oxides to be prepared on conducting substrates. This approach in turn permits the full arsenal of charged-particle spectroscopic, diffraction and imaging probes to be applied to investigations of the surface science of insulators.
Published: May 21, 2021
Citation
Chambers S.A., Y. Gao, and Y. Liang. 1995.The Early Stages of MgO Epitaxy on Lattice-Matched Cr0.7Mo0.3(001).Surface Science 339, no. 3:297-309.PNNL-SA-26276.doi:10.1016/0039-6028(95)00610-9