CAREER: Ferroic Coupling in Complex Oxide Heterostructures from First Principles

Cornell University, Ithaca NY

Investigators

Abstract

TECHNICAL SUMMARY This CAREER award supports theoretical and computational research and education that will advance a first-principles approach to materials discovery. The PI aims to elucidate the fundamental principles that govern the relationship between the atomic scale structure and the macroscopic behavior of complex oxide ferroic layered perovskites and atomic-scale heterostructures. These systems will allow a systematic investigation of several key issues including the interplay between ferroelectricity and magnetism, the emergence of ferroelectricity and oxygen octahedral rotation instabilities in reduced dimensions, ferroic proximity effects, and the functional control of complex oxygen rotation patterns that couple to properties of interest. Encouraged by recent success in developing a first-principles based model-to-materials approach and applying it to rationally design new bulk-like multifunctional materials, the PI will apply a combination of microscopic models of the solid state, basic principles of crystal chemistry, and first-principles simulations to heterostructures in order to predict a material with targeted macroscopic phenomena. In heterostructures, interfaces are key in controlling the interplay among diverse microscopic degrees of freedom prevalent in complex oxide ferroics. Ferroic systems of interest include those that are antiferroelectric, ferroelectric, antiferromagnetic, ferromagnetic, or antiferrodistortive, and those that combine more than one of these ferroic orders. In all cases, systems for which Density Functional Theory is appropriate will be considered. The close collaboration between the PI and his extensive network of experimental colleagues will be continued. The educational component of this CAREER proposal is aimed to improve the recruitment and subsequent mentoring of talented female and underrepresented minority students into the School of Applied & Engineering Physics at Cornell. To successfully implement these objectives the PI will leverage his position as the Director of "Research Experiences for Undergraduates" at the Cornell Center for Materials Research, and will collaborate with experts at Cornell in Diversity Recruitment. He will participate in programs aimed at engaging underrepresented minorities in an open discussion of science and engineering, and will work closely with the director of the Teaching Excellence Institute at Cornell to improve instructional computational modules for undergraduate students. The integrated research and outreach activities have a strong emphasis on undergraduate research-based strategies that cross disciplines and blur the line between theory and experiment. Furthermore, theory-driven materials discovery offers an exciting nontraditional interdisciplinary synergy in physics, solid-state chemistry, materials science, and computational science that will attract talented undergraduate and graduate students. NON-TECHNICAL SUMMARY This CAREER award supports theoretical and computational research and education that will advance using computers to predict the properties of materials and enable discovery based only on knowing the identity of the constituent atoms. The discovery of new materials displaying novel properties is a driving force for technological advances. Due to their highly tunable properties, structurally and chemically complex oxide materials containing elements from the transition metals in the periodic table of elements are promising classes of materials ripe for the discovery of new phenomena. An example class of materials important both scientifically and technologically is multiferroic materials which exhibit interesting responses to external fields such as becoming a magnet in response to an applied electric field. There are an enormous number of possible bulk compounds that have yet to be identified, much less experimentally synthesized and characterized. Recent advances in synthesis techniques allow artificial structuring of complex oxides at the atomic scale, greatly extending the possibilities. The PI aims to use computers and advanced theory to identify the most promising new materials for discovery through laboratory synthesis and characterization. This project will largely focus on artificially structured materials where an atomic scale interface is key in determining the macroscopic properties. The PI will use a combination of microscopic models and basic principles of crystal chemistry to develop a set of design criteria to aid in the identification of materials with desired properties built-in from the atoms up to the human scale. He will use unbiased parameter-free computational techniques to screen for candidate materials, and continue to work in close collaboration with an extensive network of experimentalists. The educational component of this CAREER proposal is aimed to improve the recruitment and subsequent mentoring of talented female and underrepresented minority students into the School of Applied & Engineering Physics at Cornell. To successfully implement these objectives the PI will leverage his position as the Director of "Research Experiences for Undergraduates" at the Cornell Center for Materials Research, and will collaborate with experts at Cornell in Diversity Recruitment. He will participate in programs aimed at engaging underrepresented minorities in an open discussion of science and engineering, and will work closely with the director of the Teaching Excellence Institute at Cornell to improve instructional computational modules for undergraduate students. The integrated research and outreach activities have a strong emphasis on undergraduate research-based strategies that cross disciplines and blur the line between theory and experiment. Furthermore, theory-driven materials discovery offers an exciting nontraditional interdisciplinary synergy in physics, solid-state chemistry, materials science, and computational science that will attract talented undergraduate and graduate students.