9315715 Birgeneau This experimental condensed matter physics project investigates (1) lamellar copper oxides, which form the basis of high temperature superconductors, and (2) model crystalline insulating magnets which are extremely disordered at the microscopic level. These interrelated materials represent problems which are at the frontiers of materials physics. For the copper oxides, understanding of both the normal and superconducting states is still remarkably primitive; while in the case of disordered magnets, sample history and irreproducibility of properties require an extension of existing understanding of equilibrium properties of materials. Neutron and x-ray diffraction will provide an atomic level picture of the magnetic properties, and how this picture changes as the structural length scale that is studied is increased. This research is of both fundamental and technical importance and may lead to production of new and higher quality superconducting and magnetic materials. %%% This experimental condensed matter physics project investigates (1) lamellar copper oxides, which form the basis of high temperature superconductors, and (2) model crystalline insulating magnets which are extremely disordered at the microscopic level. These interrelated materials represent problems which are at the frontiers of materials physics. For the copper oxides, understanding of both the normal and superconducting states is still remarkably primitive; while in the case of disordered magnets, sample history and irreproducibility of properties require an extension of existing understanding of equilibrium properties of materials. Neutron and x-ray diffraction will provide an atomic level picture of the magnetic properties, and how this picture changes as the structural length scale that is studied is increased. This research is of both fundamental and technical imp ortance and may lead to production of new and higher quality superconducting and magnetic materials. ***
