Colloquium: Nicole Benedek, Complex Oxides And Their Interfaces: Computational Approaches to Understanding and Predicting Structure

Post-doctoral Fellow, School of Applied and Engineering Physics, Cornell University

All dates for this event occur in the past.

264 MacQuigg Lab
105 W. Woodruff Ave
Columbus, OH 43210
United States

Abstract

Corrosion, thin-film growth, the conversion of sunlight into electricity in solar cells and the growth of artificial tissues may seem like disparate phenomena, but they have one thing in common: all occur at or are controlled by interfaces. Interfaces are ubiquitous and play a crucial role in the biological, chemical and physical sciences. However, despite the fundamental and technological importance of interfaces, it is currently a challenge to predict the structure an interface will adopt, or what properties it will have, under given process or environmental conditions. The general lack of structure-property relationships for interfaces hinders the design of new materials and impedes our understanding of the properties of existing materials.

In this talk, I will discuss our recent work on the use of theory and computation to understand and predict the structures and properties of complex oxides and their interfaces. First, I will describe how we are using crystal chemistry arguments in combination with first-principles calculations to create new multifunctional materials. In particular, I will show how the atomic structure of the layered perovskite Ca3Mn2O7 gives rise to its remarkable ferroelectric and magnetic properties.[1] I will then describe, using SrTiO3 as an example (an important material in the pursuit of all-oxide electronics), a general computational approach to predict the structures and free energies of grain boundaries and heterophase interfaces with fixed stoichiometric and non-stoichiometric compositions.[2] Our results suggest new ways to start understanding, exploring and designing complex oxide interfaces.

[1] N.A. Benedek and C.J. Fennie, Phys. Rev. Lett. 106 107204 (2011); Physics Viewpoint 4 18 (2011); Nature Materials News & Views 10 269 (2011).
[2] A.L.-S. Chua, N.A. Benedek, et al, Nature Materials 9 418 (2010).

Bio

Nicole Benedek is a Postdoctoral Fellow in the School of Applied and Engineering Physics at Cornell University. Her research is focused on using theory and first-principles simulations to design, predict and understand the structures and properties of functional materials, especially complex oxides. She recently discovered a new route to achieve electric-field control of the magnetization (one of the 'holy grails' of functional materials research) in a class of layered perovskite oxides. Before joining Cornell, Dr. Benedek worked in the groups of Profs. Mike Finnis and Adrian Sutton at Imperial College London. At Imperial, she studied the structures of grain boundaries in complex oxides and developed a computational technique for predicting interface structure. She is also interested in the ways in which theory and computation can be combined with electron microscopy and spectroscopy techniques to advance our understanding of materials, particularly interfaces. Dr. Benedek holds a PhD in Applied Physics and Applied Chemistry and a B. App. Sci. in Applied Chemistry, both from RMIT University, Australia.