Tailoring interface functionality of complex oxide heterostructures - A neutron and x-ray study

Michigan State University, East Lansing MI

Investigators

Abstract

Non-technical Abstract: Complex transition-metal oxide heterostructures represent an emerging and rapidly growing field with both significant scientific merits and potential applications in spintronics, catalysts, solar cells, etc. A plethora of novel physical phenomena can arise at the interface of dissimilar materials in oxide heterostructures that are not attainable in the bulk constituents. This project investigates such novel phenomena in transition-metal oxide heterostructures via creation and manipulation of novel interface functionalities by tuning the substrate geometry and surface orientation. Importantly, this project serves as a platform to train the next-generation neutron and synchrotron x-ray scattering scientists, helping to promote the user community of the cutting-edge facilities in national laboratories. In addition to training graduate and undergraduate students, this project also supports the scientific research activities engaging high school teachers and K-12 students, as well as the activities of developing and presenting workshops to students in community colleges in Michigan. Technical Abstract: The project investigates the emergent quantum phenomena in correlated transition-metal oxide heterostructures via creation and manipulation of novel interface functionalities. Tuning the substrate geometry and surface orientation gives rise to diverse polar surface terminations, bond connections, and octahedral distortions, which are anticipated to affect electronic and orbital reconstruction as well as magnetic and structural coupling at the interfaces. Consequently, this can drastically alter physical properties of oxide heterostructures grown atop, providing a pathway to new physics and materials research. This project utilizes two unique and complementary techniques, i.e., polarized neutron reflectometry and polarized x-ray absorption spectroscopy, which offer high depth resolution and characteristic fingerprint of transition-metal elements to decisively determine the nature of interfacial magnetic and electronic states.