Molecular beam epitaxial growth of complex novel oxides

Many potential model materials for studying highly correlated electron systems in the oxides are currently grown as bulk materials under high pressures of oxygen. This style of growth does not lend itself to experiments which require clean and controlled interfaces, making it very desirable to grow these materials via Molecular Beam Epitaxial-type processes (MBE). For MBE growth of these ‘high pressure’ materials, two constraints must be met. Enough highly active oxygen must be present during growth to allow the correct oxidation states to form, and a means to stabilize the desired structure must be present. The following have played a critical role in trying to satisfy and understand these constraints: the development of an atomic oxygen source and detection scheme that greatly increases the oxygen activity parameter space obtainable during MBE growth; development of a new means of real-time, in situ, three-dimensional structural determination; and the extended use of core level photoelectron spectroscopy for in situ chemical analysis. Using these technologies, the ability to grow several of these ‘high pressure’ materials (namely, CrO ₂ and SrCu₂O₃) has been investigated.