Investigation of Magnetism in Discrete Rare-Earth Clusters and Low Dimensional Solids

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

This project aims to investigate magnetism in discrete rare-earth clusters and low dimensional solids. In magnetic materials, 4f moments provide intrinsic magnetic anisotropy that is central to the function of hard permanent magnets. The goal is to investigate the interplay between the electronic features that are characteristic of the delocalized (5d and 6s) electrons in 2-, 1-, and 0-dimensional (cluster) compounds and the localized (magnetic) 4f electrons. Studies of rare-earth clusters and low-dimensional solids that integrate synthesis, properties measurements, and limited use of computational methods for interpretation and understanding of properties will be emphasized. The project builds on the results of exploratory synthetic investigations of rare-earth solids (mostly halides) that have been ongoing for three decades, but which have so far seen limited systematic investigation of magnetic properties and almost no theoretical analysis. Since low-dimensional compounds often exhibit structural instabilities (e.g., Peierls and Jahn-Teller distortions in 1- and 0-dimensional systems, charge-density wave phenomena in 2-D), the possibility of structural transitions coincident with magnetic transitions will be explored, thus yielding first-order magnetic transitions characteristic of giant-magnetocaloric materials. The lanthanide elements play an important role in a variety of technologies - many, perhaps most, of which rely on the unique role that their f-electrons play in their chemistry. Their optical properties play an essential role in lanthanide-containing laser materials. In magnetic materials, lanthanides are central to the function of hard permanent magnets. In this project, we will investigate whether lanthanide-containing molecules might function as molecular magnets - the smallest conceivable 'bar-magnets'. If so, lanthanide-containing molecules could help provide nanotechnological information storage capacity that would far outstrip current hard-drive technologies. Also of interest are lanthanide-containing materials whose magnetic properties, structural properties, and thermal properties are coupled. Such materials are promising in a new generation of magnetic refrigerators with efficiencies that exceed current refrigeration technology. The training of students, undergraduate and graduate, as well as postdoctoral fellows, to compete well for industrial and academic positions in areas such as these continues to be a priority.