Exploring the functional behavior of domain walls in wurtzite ferroelectrics

The National Science Foundation Division of Materials Research awarded the Board of Regents of the University of Nebraska $780,000 on September 1, 2026, for research exploring the functional behavior of domain walls in wurtzite ferroelectric materials under the Mathematical and Physical Sciences program (CFDA 47.049).

The research investigates the atomic structure, field-induced switching dynamics, and electronic transport behavior of domain walls in wurtzite-structured ferroelectric thin films. Domain walls are nanometer-wide regions separating areas with different polarizations; the project probes how these boundaries behave and can be controlled to enable next-generation compact, energy-efficient electronics and memory technologies. The work focuses on aluminum nitride alloy ferroelectrics, which are semiconductors compatible with modern manufacturing methods.

The project integrates research with education and public outreach. Activities include dedicated science camps for middle and high school students, professional development for high school science teachers from resource-limited rural areas delivered through virtual seminars and laboratory demonstrations, and online multimedia platforms communicating materials science concepts to the general public.

Performance occurs in Lincoln, Nebraska, with a period of performance from September 1, 2026, through August 31, 2029. The award is classified as a Project Grant, an assistance type.

Abstract

Nontechnical description ferroelectrics are a broad family of electronic materials that that share one specific characteristic: they have a spontaneous electrical polarization that can be switched. This makes them attractive for technologies such as high-speed electronics and energy efficient computing. This project studies a recently discovered class of ferroelectrics based on aluminum nitride alloys. These breakthrough materials are semiconductors and are compatible with modern manufacturing methods. The focus of the research is domain walls, which are nanometer wide regions that separate regions with different polarizations. Domain walls are found in almost every technologically relevant ferroelectric material. These domain walls can have extraordinary properties, such as high electrical conductivity, that differ completely from the surrounding material. The research team probes how these tiny boundaries behave and how they can be controlled. Understanding them could enable the next generation of compact, energy-efficient electronics and memories. The project integrates research with education and public outreach. These efforts include dedicated science camps to engage middle school and high school students. The research team provides professional development opportunities for high school science teachers from resource-limited rural areas through virtual seminars and laboratory demonstrations. They will also use online multimedia platforms to communicate materials science concepts to the general public. Technical description the scientific objective of this project is to determine the atomic structure, field-induced switching dynamics, and electronic transport behavior of domain walls in wurtzite-structured ferroelectric thin films. While prior research primarily addresses bulk polarization switching and device integration in these systems, the microscopic mechanisms governing their domain boundaries remain largely unexplored. This research addresses three fundamental questions: the atomic configuration of neutral 180-degree and charged domain walls; the complex interplay between domain wall mobility, defect chemistry, and strain; and the microscopic origin of domain wall conductivity. Due to the wide bandgap, strongly covalent bonding environment, and large internal stress characteristic of wurtzite materials, domain wall behavior is expected to differ profoundly from that of conventional perovskite oxides. The research team uses an integrated approach that combines thin-film synthesis, post-growth defect engineering, advanced nanoscale characterization, and predictive modeling. Post-growth defect landscapes are modified through controlled helium-ION irradiation. Structural and chemical characterization at the atomic scale is conducted via high-resolution scanning transmission electron microscopy combined with in situ electrical biasing and electron energy-loss spectroscopy. Nanoscale domain wall dynamics, electromechanical properties, and localized electrical conduction are investigated using a set of scanning probe microscopies. These experimental efforts are integrated with first-principles electronic-structure calculations based on density-functional theory to predict stable domain wall configurations, resolve localized defect states, and map the energy landscapes governing polarization reversal. This comprehensive research provides a mechanism-based framework to understand and tailor domain wall functionalities, directly supporting the development of adaptable nanoelectronic and memristive elements in wide-bandgap semiconductor systems. 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.- subawards are planned for this award.