Systematic Neutron Scattering Investigation of Structural Evolution in Pyrochlores at Low and High Temperatures

POSTER

Abstract

Pyrochlore structures R$_{2}$Ti$_{2}$O$_{7}$ (with R being a rare earth element) belong to the Fd-3m space group and the family of rare earth titanates. Recently, pyrochlores have attracted great attention as nuclear waste form and possible high temperature solid oxide fuel cell (SOFC) materials. Furthermore, Dy$_{2}$Ti$_{2}$O$_{7}$ was reported by several authors to be the first structure in which magnetic monopoles were observed. This latter observation is related to the existence of spin ice in these structures, a phenomenon referring to a geometrical frustrated magnetic system, whereby ``frustration'' describes the effects that occur when interactions of similar strength compete and prevent a system from settling into a unique ground state. In spin ices, like Dy$_{2}$Ti$_{2}$O$_{7}$, only the rare-earth atoms have a magnetic moment and these cations reside in a network of corner sharing tetrahedra forming the pyrochlore lattice. Here we present structural parameters such as cation ordering, bond lengths and bond angles to quantify the geometrical frustration and characterize the crystal structure over a temperature range from $\sim $5K to 1300K.

Authors

  • Adrian Losko

    Los Alamos National Laboratory

  • Sven Vogel

    Los Alamos National Laboratory

  • Andrew Polemi

    Utah State University, Brigham Young University, University of Pennsylvania, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, High Altitude Observatory, University of Colorado at Boulder, Massachutes Institute of Technology, Utah Valley University, University of New Hampshire, Applied Physics Laboratory, Johns Hopkins University, University of Montana, Southwest Research Institute, University of Southern California, Lockheed Martin Advanced Technology Center, University of Chicago, Massachusetts Institute of Technology, SciPrint.org, Centre National de la Recherche Scientifique, Colorado State University, V. Alecsandri College, Bacau, Romania, Colorado School of Mines, National Renewable Energy Laboratory, Utah State University, Department of Physics, Brigham Young University, Provo, Huntsman Cancer Institute, Brigham Young University - Idaho, University of Arizona, Florida State University, Weber State University, Brigham Young University - Provo, New Mexico State University, Colorado State University, Fort Collins, CO 80523

  • Andrew Polemi

    Utah State University, Brigham Young University, University of Pennsylvania, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, High Altitude Observatory, University of Colorado at Boulder, Massachutes Institute of Technology, Utah Valley University, University of New Hampshire, Applied Physics Laboratory, Johns Hopkins University, University of Montana, Southwest Research Institute, University of Southern California, Lockheed Martin Advanced Technology Center, University of Chicago, Massachusetts Institute of Technology, SciPrint.org, Centre National de la Recherche Scientifique, Colorado State University, V. Alecsandri College, Bacau, Romania, Colorado School of Mines, National Renewable Energy Laboratory, Utah State University, Department of Physics, Brigham Young University, Provo, Huntsman Cancer Institute, Brigham Young University - Idaho, University of Arizona, Florida State University, Weber State University, Brigham Young University - Provo, New Mexico State University, Colorado State University, Fort Collins, CO 80523