MD3Tutorial

The tutorial will provide foundational knowledge for researchers, ranging from students to professional scientists, in the field of the design of complex oxide thin films and heterostructures. Participant outcomes will include understanding routes to predict, synthesize, control, and explain the functional properties of complex oxide heterostructures with a focus on theoretical approaches and synthetic methods. The tutorial will be divided into three presentations covering theoretical and experimental approaches. In each segment, the instructor will highlight how experiment and theory can work together to design targeted materials structure-property relationships in oxide heterostructures.

1:30 pm-2:30 pm
Part I: James Rondinelli

Part I focuses on computational design oxide heterostructures by first principles approaches. It will include theoretical approaches for predicting and understanding ground state structures and properties in thin films and heterostructures. The main topics to be discussed include (1) basic chemistry and electronic structure of complex oxides, (2) structured-based design approaches for new functionality in oxide heterostructures, including strain engineering and polyhedral control, (3) density functional theory methods for calculation the ground state of complex oxides under various mechanical constraints, and (4) open questions and new opportunities at oxide interfaces, including proximity effects, phononic coupling and gradients in order parameters.

2:30 pm-3:00 pm Break

3:00-4:00 pm
Part II: Hans Christen

Part II provides a general introduction to pulsed-laser epitaxy, its successes and limitations and its future. From the perspective of complex-oxide research, pulsed-laser deposition has been crucial in advancing the field, with many of the key discoveries being enabled by this approach (high-temperature superconducting films, room-temperature multiferroics, 2D conductivity at perovskite interfaces). While pulsed-laser deposition is conceptually simple, the technique has seen significant advances in recent years; modern pulsed-laser epitaxy yields samples that have precise stoichiometries, abrupt interfaces and low defect densities. At the same time, the approach provides access to an enormously broad range of deposition parameters, which enables the growth of metastable materials, nanostructures, and superlattices, and is thus the design of new materials. This segment will emphasize growth dynamics, surface evolution and the interplay between chemical and physical phenomena, in situ diagnostics, new instrumentation and the importance of these issues for the further development of the deposition technique and for oxide heterostructure research in general.

4:00 pm-5:00 pm
Part III: Steven May

Part III covers experimental design of oxide heterostructures by molecular beam epitaxy (MBE). Molecular beam epitaxy is one of the most powerful synthesis techniques for growing oxide heterostructures, due to the high degree of crystalline quality and monolayer precision it enables, and the wide variety of chemistries and crystal structures that can be realized. This segment will begin by describing the basic principles of molecular beam epitaxy, the modifications needed for the growth of oxides and the history of its use in oxide synthesis. The relative advantages and disadvantages of MBE compared to other oxide growth techniques will be discussed. The latter half will provide a forward-looking perspective on emerging opportunities based on oxide MBE, including in situ characterization techniques that can be integrated with MBE, the growth of complex oxides beyond ABO₃ perovskites, growth of superlattice structures with more than two constituent materials, and post-growth approaches for expanding the array of epitaxial oxides that can be realized.

Instructors:

• Hans Christen, Oak Ridge National Laboratory
• Steven May, Drexel University
• James Rondinelli, Northwestern University