This project is co-supported by the Condensed Matter Physics Program and the Metals Program. The research is focused on small magnetic particles, with emphasis on rare-earth nanoparticles and nanocomposites. The work relies on a new sputtering technique which produces pure nanoparticles with controlled size while simultaneously embeding them in an inert matrix. The objectives are (1) to prepare nanoparticles of rare earth metals and rare earth intermetallic compounds and to study their fundamental and technological properties including size and surface/interface effects, and (2) to fabricate simple nanocomposite structures consisting of hard (soft) nanoparticles embedded in soft (hard) matrices and to study magnetization reversal mechanisms. The large surface area in nanoparticles, together with properties of the long range RKKY exchange interaction is expected to lead to a variety of magnetic structures and magnetic phenomena quite different from those found in the bulk forms of the magnetic materials. The nanocomposite materials will allow the study of magnetic hysteresis, including the domain wall pinning and nucleation of reverse domain structures. %%% This project is co-supported by the Condensed Matter Physics Program and the Metals Program. The work deals with the fundamental and technological properties of rare earth nanoparticles and nanocomposites. These particles, with a size of a fraction of a millionth of an inch, have properties which make them attractive for both ultrahigh density magnetic recording, and permanent magnet applications. This research offers excellent training and educational opportunity for graduate students and post-docs within a divers interdisciplinary program focused on magnetic materials. The students will be trained in state-of-the art methods, such as fabrication of nanoparticles, imaging with transmission electron microscopy, structural characterization with x-ray diffraction, and magnetic measurements with modern magnetometry techniques.
