9418991 MacLaughlin Electronic structure, magnetism, and superconductivity in highly correlated electron materials will be investigated using nuclear magnetic resonance and muon spin rotation techniques. The research uses the sensitivity of these two techniques to microscopic (atomic) charge and spin correlations as tools to probe local effects of strong electron correlation. The techniques will be used to study four different systems: 1) spin susceptibility, charge and spin dynamics in lanthanum based planar cuprates and nickelates which exhibit quantum and anti ferromagnetism, 2) spin-liquid behavior and effects of defects (chain breaks, hole doping) in Haldane chain compounds, 3) non-Fermi-liquid properties of Kondo alloys and heavy-fermion compounds, and 4) dynamics of low-lying superconducting excitations in uranium based heavy-fermion superconductors. %%% Understanding effects of correlations between electrons on magnetism and conduction in solids remains an important unsolved problem in condensed matter physics. This research uses magnetic resonance techniques as a probe of correlated- electron behavior at the atomic level. In magnetic resonance, the weak but measurable magnetism of probe" magnetic moments, (e.g. nuclei) is used to "spy" on the local magnetic environment of the probes, which do not seriously perturb their surroundings. The research seeks better understanding of the behavior of 1) oxide magnets closely related to high-temperature superconductors, and 2) the so-called heavy-electron metals, in which electrons behave as if they were hundreds or even thousands of times more massive than the free electrons. The work will involve university, government laboratory, industrial and international collaboration. ***
