Collaborative Research: DMREF: Accelerated Discovery of Artificial Multiferroics with Enhanced Magnetoelectric Coupling

Non-technical Description: Developing new materials lays the foundation for technology innovations. When one material is integrated with another, new properties and functionalities can emerge in the resulting heterostructure. The choice of building blocks, however, is a challenge that is best addressed with a collaborative approach combining computational methods, material synthesis, and a broad range of characterization methods.

This research will tackle a long-standing material science challenge: how to create multiferroics materials that combine long-range electric and magnetic orders. Artificial multiferroics consisting of layered magnetic two-dimensional (2D) materials interfaced with ferroelectric 2D or oxides materials will be investigated. Because the interface between the electrically ordered (ferroelectric) layer and magnetically ordered (e.g., ferromagnetic) layer is atomically flat, an enhanced coupling between the two can be used to effectively switch the magnetic order via the electrical control.

These new materials can lead to technological innovations, e.g., memory devices that are compact and power-saving. Given the large number of possible choices of 2D materials, machine-learning based data mining will lead the experimental effort in synthesis and characterization of new multiferroic heterostructures in this research.

Technical Description: Multiferroics are materials that simultaneously exhibit long-range electric and magnetic orders. The coupling between the electrical and magnetic polarizations, i.e., the magnetoelectric (ME) effect, can be exploited to develop low-power nanoelectronics based on voltage-control of magnetism. This research will accelerate the discovery of a new type of artificial multiferroics with enhanced magnetoelectric coupling by integrating two-dimensional (2D) van der Waals (vdW) magnets with vdW or oxide ferroelectrics.

The ME effect in single-phase materials is typically weak because ferroelectricity and magnetism come from different electronic orbitals. ME coupling in synthesized composites, on the other hand, occurs exclusively at inter-materials boundaries, with small interface/bulk ratios and limited material choices. The hypothesis that a significantly enhanced ME effect can be achieved in heterostructures composed of a magnetic vdW layer and a ferroelectric vdW or oxide material will drive this integrated research activity.

With a large number of established 2D magnetic and ferroelectric materials, the possible combinations of heterostructures can reach an order of 10,000 to 100,000. A computation-led approach is thus critical to accelerate the discovery of optimal artificial multiferroics with an enhanced ME effect. In this project, the predictions of new multiferroic heterostructures will be validated by materials synthesis and characterization experiments.

In addition to the research efforts, this award will support the training and education of graduate and undergraduate students as the next-generation scientific and engineering workforce. This project will also develop contents and posts for social media to introduce concepts and developments of multiferroic quantum materials to engage the general public.

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.