Statics and Dynamics of Spatially and Dimensionally Constrained Oxides

Northwestern University, Evanston IL

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: The past couple decades have witnessed remarkable advances in nanostructured and multifunctional ceramic oxides to harness their unusual non-linear properties. Ferroelectric (FE) and ferromagnetic (FM) oxides, in particular, have received considerable attention due to their technological prospects for non-volatile memories and storage media, respectively. However, there remain many open questions in term of the detailed understanding of FE and FM phenomena as a function of their dimensional parameters and the nature of the interfaces. This project addresses innovative patterning approaches for creating nanoscale architecture of multifunctional oxides, and the role of spatial and dimensional confinement. The research is expected to provide predictive strategies and design rules for nanopatterned oxides for harnessing their useful properties. The project also involves experiential and immersion opportunity for journalism students to follow the process of creativity in scientific pursuits, and for science and engineering students to learn about the process of reporting and communication. TECHNICAL DETAILS: The scientific underpinning of the research revolves around understanding of the decisive role of spatial and dimensional constraints on microstructural evolution, localized characteristics of interfaces, and size/shape-specific properties/phenomena in FE/FM oxides. Embedded in the scientific quest are nanopatterning techniques for complex oxides. Innovative hybrid approaches based on beam-pen lithography (BPL) are coupled to soft chemistry (sol-gel) to generate large area oxide nanopatterns. This approach is necessary to address critical scientific issues associated with phase transformation (crystallization) and phase separation under confinement. Advanced techniques of X-ray scattering and electron microscopy are expected to unravel, down to atomic scale, the nature of interfaces between substrate and nanopattern and the dynamics of ferroelectricity and magnetism as a function of nanopattern parameters and substrate constraints. The research students, including graduate students and undergraduate interns, are trained in advanced microscopy and characterization tools and techniques which are essential for modern materials developments.