The goal of this project is to demonstrate a new family of nanoferroic multifunctional devices, based on shape-memory Heusler alloy films in ferroelectric heterojunctions, where resistance, magnetic and structural properties of the Heusler alloys will be switchable by applied electric field. Heusler alloys are a group of intermetallic compounds that have unique and interesting electro-magnetic behaviors, including the magnetic shape-memory effect. Selected shape-memory Heusler alloys are expected to be better than manganite-based compounds because their transformations can be controlled to occur near room temperature. This research attempts to distinguish the roles of electronic and strain-mediated coupling between layers in heterojunctions in order to determine the origin of each effect. It also attempts to identify the mechanism of the martensitic phase transformation in the Heusler alloy films. It is ultimately envisioned that this research may lead to a new class of nanoferroic multifunctional devices enabling new sensor and electronic applications. These devices will have a potential for use in memory, sensors and magnetic refrigeration. Long-established participation of high-school teachers and their students in the research laboratories of the investigators will be enhanced. Graduate and undergraduate students will be educated and trained through research activities.
NON-TECHNICAL SUMMARY: The magnetic shape-memory effect in Heusler alloy films will be used to explore physical behaviors of these alloys alone and when paired with other materials to make a functional device. It is ultimately envisioned that this research may lead to a new class of nanoferroic multifunctional devices enabling new sensor and electronic applications. These devices will have a potential for use in memory, sensors and magnetic refrigeration. Long-established participation of high-school teachers and their students in the research laboratories of the investigators will be enhanced. Graduate and undergraduate students will learn nanofabrication techniques, chemical synthesis, sensitive electrical measurements, and theory of quantum transport and magnetization dynamics, providing hands-on experience suitable for their further research and development in leading industrial and academic laboratories.
