Branton J. Campbell
ProfessorDepartment of Physics & Astronomy
Brigham Young University
Provo, UT 84602, USA
Tel: 801-422-5758, Fax: 801-422-0553
I apply state-of-the-art x-ray and neutron scattering techniques to study local and long-range structures in a variety of complex solids, including fast-ion conductors, ferroelectric relaxors, high-temperature superconductors, and colossal magnetoresistive manganites, where nanoscale structural features influence macroscopic physical properties. This includes the development of symmetry-mode analysis as a tool for the determination, refinement and interpretation of distorted structures involving lattice strains, atomic displacements, magnetic moments and occupational orderings at both commensurate and incommensurate wavevectors.
solved. Unlike their hole-doped cousins, these crystals do not superconduct when newly grown, but only after a high-temperature treatment in a reducing environment. Using a combination of x-ray diffuse scattering and neutron powder diffraction techniques, their copper-oxide sheets were found to be initially riddled with copper-vacancy defects, which were then reversibly repaired during heat treatments.