Harnessing unconventional structural degrees of freedom to design new hybrid layered perovskites

NONTECHNICAL SUMMARY

This award supports theoretical and computational research and education that aims to use computers to predict and understand the properties of a class of hybrid organic-inorganic oxide materials. Advanced materials shape many of the aspects of modern life, from smart electronics to high-speed communications and renewable energy sources. Despite this, the discovery of materials with technologically useful properties is a slow and difficult process.

The development of advanced computational techniques, based on the fundamental laws of physics, together with vast increases in computer power, have transformed the way scientists investigate, discover and design materials for particular applications. For example, the properties of as-yet unsynthesized materials can be predicted and studied using computer simulations, such that experimentalists can focus their efforts on the most promising materials families or compositions.

In this project, the PI will investigate the relationship between the chemical composition of a class of hybrid organic-inorganic oxide materials and their lowest-energy structure and physical properties, such as their ability to develop spontaneous polarization that is switchable by applying external electric fields. The aim is to develop a chemically intuitive theory that experimentalists can use to quickly filter promising materials out of the vast number of candidate materials.

The results of computer simulations will be validated through close collaboration with experimentalists.

This award will also support (i) the PI's scientific workforce development efforts by establishing an exchange program between the PI's group and the Inorganic Chemistry Laboratory at the University of Oxford, UK, with an aim to promote collaboration and knowledge/skills exchange between theoretical/computational groups and experimental groups, and (ii) curricular development efforts at the PI’s institution by introducing and further developing evidence-based techniques into classroom instruction and class design to assist students in formulating effective learning strategies.

TECHNICAL SUMMARY

This award supports theoretical and computational research with an aim to elucidate the fundamental physical and chemical factors underlying the structural basis of ferroelectricity and magnetoelectricity in a series of hybrid organic-inorganic Dion-Jacobson oxides. Hybrid organic-inorganic perovskites can exhibit unique structural degrees of freedom; they are unconventional in the sense that they are not observed, and may even be forbidden, in their fully inorganic counterparts.

However, in contrast with hybrid halide perovskites, hybrid oxide perovskites have not been explored in detail. In addition, in comparison with inorganic perovskites, the development of a chemically intuitive, microscopic theory that connects the physical mechanisms of particular structural distortions in hybrid organic-inorganic layered perovskite oxides to bonding and crystal chemistry is almost non-existent.

In this project, using symmetry principles, first-principles density functional theory calculations and crystal chemical models, the PI will uncover the fundamental knowledge of crystal chemistry and physical mechanisms of ferroelectricity that will enable rational design of hybrid organic-inorganic layered perovskite oxides. The successful completion of this research program is expected to result in the establishment of a new materials platform for designing and discovering novel hybrid organic-inorganic layered perovskites.

This award will also support (i) the PI's scientific workforce development efforts by establishing an exchange program between the PI's group and the Inorganic Chemistry Laboratory at the University of Oxford, UK, with an aim to promote collaboration and knowledge/skills exchange between theoretical/computational groups and experimental groups, and (ii) curricular development efforts at the PI’s institution by introducing and further developing evidence-based techniques into classroom instruction and class design to assist students in formulating effective learning strategies.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.