Excellence in Research: Nano-Structured Functional Ferromagnets

NON-TECHNICAL SUMMARY:

Magnetostrictive materials are those that can elongate or contract when exposed to an external magnetic field. Highly magnetostrictive materials with a reversible magnetic character are highly suited for applications in modern technology such as sensors, actuators, and underwater communication devices. This research advances scientific knowledge of nanostructured ferromagnets that display a large mechanical response under small magnetic fields.

A variety of magnetic materials are studied, including metallic alloys and ceramics in the bulk and thin film forms. This research program offers unique opportunities in the education and training of graduate and undergraduate students in materials synthesis and state-of-the-art characterization techniques. These efforts increase the competitiveness of minority students in the Science and Engineering disciplines and expand the pool of talented African-American scientists and engineers, thereby enhancing the high-technology minority workforce.

The outreach to Maryland high schools engages and encourages high-school students in science and engineering. TECHNICAL SUMMARY:

This award supports research on magnetic materials combining small magnetocrystalline anisotropy with large magnetostriction. The hypothesis is that the fundamental mechanism giving rise to this unusual combination of properties consists of breaking the theoretical spin-orbit coupling link valid for single-phase solids via a two-phase nanostructures.

The systems of study include Fe-Ga,Al,Ge solid solutions and nanostructured cobalt ferrite in the form of nano-chessboard whose properties are probed by magnetic characterization techniques. Diffraction techniques using x-ray and neutron radiation determine the underlying nanostructures. Transmission electron microscopy of these model materials under stress in situ are also crucial experiments to elucidate the role of the nanostructure in magnetostriction.

These activities aim at the development of a common science foundation for this materials class. The engagement of both undergraduate and graduate students in this research builds research experience and expertise in the field of magnetic materials.

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.