Multi-source MBE with high-precision rate control system as a synthesis method sui generis for multi-cation metal oxides

Molecular beam epitaxy (MBE) has been an excellent tool to design artificial heterostructures in the research field of semiconductors by means of an alternate stacking of existing lattices. This article describes further capabilities of MBE as a synthesis tool sui generis, especially for multi-cation oxides, due to low-temperature reaction and the pseudomorphic stabilization effect by epitaxy. Single-crystalline Sr0.9La0.1CuO2 films exhibiting metallic conduction and superconductivity are successfully prepared by MBE. A new phase, T⁎-La2CuO4, is also stabilized on a DyScO3 substrate. Methods of high-precision rate control of each constituent element, which is prerequisite for a reproducible growth of the multi-cation oxide films, are also discussed.

highlights
► Capability of MBE as a synthesis tool of multi-cation oxides is demonstrated.
► MBE-grown Sr0.9La0.1CuO2 films are metallic and superconducting with a Tc of 41 K.
► A new phase, T⁎-La2CuO4, is stabilized on a DyScO3 substrate due to epitaxy.