Showing 211 results for Author: Eugene Mamontov
Sep, 2008
Conference Paper
Abstract The instruments in the extensive suite of spectrometers at the SNS are in various stages of installation and commissioning. The Back Scattering Spectrometer (BASIS) is installed and is in commissioning. It's near backscattering analyzer crystals provide the 3 �eV resolution as expected. BASIS will enter the user program in the fall of 2007. The ARCS wide angular-r…
Aug, 2008
Journal
The high energy resolution, coupled with the wide dynamic range, of the new backscattering spectrometer (BASIS) at the Spallation Neutron Source, Oak Ridge National Laboratory, has made it possible to investigate the diffusion dynamics of hydration water on the surface of rutile (TiO2) nano-powder down to a temperature of 195 K. We attribute the dynamics measured on the BA…
Oct, 2007
Journal
Quasielastic neutron scattering (QENS) experiments carried out using time-of-flight and backscattering neutron spectrometers with widely different energy resolution and dynamic range revealed the diffusion dynamics of hydration water in nano-powder rutile (TiO2) and cassiterite (SnO2) that possess the rutile crystal structure with the (110) crystal face predominant on the…
Oct, 2007
Journal
Quasielastic neutron scattering was used to probe the diffusion of water molecules in 2.3 molal CaCl2 solution confined in 100 % hydrated Vycor glass in the temperature range of 220 K to 260 K. We observed a gradual transition from the restricted diffusion regime at lower temperatures to unrestricted diffusion regime at higher temperatures. The diffusion parameters were co…
Oct, 2007
Conference Paper
Although neutron scattering is often considered a bulk probe, we demonstrate that the mobility of surface water on oxide nano-powders can be investigated using quasielastic neutron scattering. We discuss how the reduced number of hydrogen bonds per water molecule associated with surface confinement leads to a qualitative modification of single-particle translational dynami…