FY2010 - Oak Ridge National Laboratory

Director’s R&D Fund—
Neutron Sciences
05901
New Neutron Scattering Experiments at the Spallation Neutron Source
Gregory S. Smith
Project Description
ORNL has the world’s highest flux user facility for neutron scattering, the Spallation Neutron Source
(SNS). Neutron scattering is a powerful tool to study the structure and dynamics of materials. Several
specialized techniques at SNS provide information on materials at a wide range of length (0.1–100’s nm)
and time (10 -6 –10 -15 s) scales. The information gleaned from neutron scattering experiments is invaluable
in characterizing materials for a variety of technological and scientific applications. Because of the
diversity of studies that can be performed at the SNS, to fully utilize the capabilities of this unique
national facility, collaborations need to be established with researchers from many disciplines and
institutions. This project will support new experimental studies of advanced materials utilizing a broad
suite of instruments at the SNS.
Mission Relevance
A key component of this project is to build new collaborations with external scientists at universities and
industry to exploit neutron scattering techniques to understand materials’ properties. This will ultimately
produce more science at the SNS, a key DOE Basic Energy Sciences user facility. The major portion of
the project funds are used to support travel for new users to the SNS and eventually to the High Flux
Isotope Reactor (HFIR) facilities. By funding travel costs for new students and post-docs to participate in
neutron scattering experiments, we expect to build a stronger future program by introducing new
researchers to the capabilities of neutron scattering techniques. In addition, the larger teams of
experimenters funded by this project will be better able to take advantage of these facilities provided by
the DOE.
Results and Accomplishments
This project was initiated in August 2010. The major accomplishment was to organize the research
scientists on the SNS beamlines to help identify experimenters already planning to come to the facility in
September. Then, each of the teams was contacted and encouraged to bring extra students or post-docs to
increase the scientific effectiveness of their experiments. The funding for those extra scientists was
provided though this project. This resulted in 18 new users to the facility working on nine different
scientific topics: (1) magnetic reconstructions at a polar antiferromagnetic thin film surface; (2) hydrogen
dynamics in lithium borohydride confined to nanoporous carbon aerogels; (3) structure determination of
new negative thermal expansion phases MgHfW 3 O 12 , MgZrW 3 O 12 , MgHfMo 3 O 12 , MgZrMo 3 O 12 ;
(4) powder neutron diffraction studies on Yb 3 Ga x Ge 10-x (x = 6–8) compounds; (5) neutron scattering and
reflectivity on P3HT/PCBM bulk heterojunction solar cell devices; (6) magnetic phasing of neutron
reflectivity from reconstituted single membranes containing the vectorially oriented voltage sensor;
(7) polarized neutron reflectivity on Fe 16 N 2 thin film with giant saturation magnetization; (8) structural
studies of semiconductors for solar water splitting: oxygen vacancies and nitrogen doping; and
(9) neutron reflectometry studies of the relation between the film structure and the electrical properties of
layer-by-layer assembly. The data from all of these experiments are being analyzed.
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