HR: 0800h
AN: MR11A-0921    [Abstracts]
TI: Neutron Diffraction and Local Atomic Structure of Fontainebleau Sandstone: Evidence for an Amorphous Phase?
AU: * Page, K
EM: kpage@lanl.gov
AF: Los Alamos National Laboratory, Lujan Neutron Scattering Center LANSCE-12, MS H805, Los Alamos, NM 87545 United States
AU: Proffen, T
EM: tproffen@lanl.gov
AF: Los Alamos National Laboratory, Lujan Neutron Scattering Center LANSCE-12, MS H805, Los Alamos, NM 87545 United States
AU: Darling, T W
EM: darling@lanl.gov
AF: Los Alamos National Laboratory, Materials Science and Technology MST-10, MS K764, Los Alamos, NM 87545 United States
AU: TenCate, J A
EM: tencate@lanl.gov
AF: Los Alamos National Laboratory, Earth and Environmental Sciences Geophysics, MS D443, Los Alamos, NM 87545 United States
AB: Total neutron scattering measurements of solid Fontainebleau sandstone were carried out. Standard Rietveld analysis, yielding only average structural information, reveals that the long range average structure of this sandstone is pure quartz. Atomic pair distribution function (PDF) analysis, however, shows significant local structural deviations from the quartz structure. These deviations manifest themselves as an excess of 5-10% of nearest neighbor (NN) Si-O and O-O bonds. No evidence of deviations from the average quartz structure can be found for atom-atom separations larger that the NN O-O bond. This could be understood as an additional glassy SiO$_2$ phase being present in the sandstone. [Work supported by Los Alamos Institutional Support (LDRD) and the DOE Office of Basic Energy Sciences. The Manuel Lujan Jr. Neutron Scattering Center is a national user facility funded in part by the U.S. DOE.]
DE: 3630 Experimental mineralogy and petrology
DE: 3694 Instruments and techniques
DE: 3909 Elasticity and anelasticity
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting