FY2010 - Oak Ridge National Laboratory

Director’s R&D Fund—
Advanced Energy Systems
energy efficiency improvements of 20–30% in excess of conventional, gas-compression refrigeration
technology. Magnetic heating and cooling occur with the magnetization and demagnetization of MCE
materials and can be incorporated into highly efficient heat pump cycles. The project directly supports
the Building Technologies Program’s High Priority R&D goal of “developing new, highly energyefficient
HVAC equipment that will significantly reduce overall energy needs in new and existing
commercial buildings.”
Results and Accomplishments
This project uses an integrated computational and experimental approach. A computational model of the
MCE in Ni 2 MnGa based on ORNL’s leading first-principles modeling code, Locally Self-consistent
Multiple Scattering (LSMS), has been developed and run on 28,800 Jaguar processors using 200 Monte
Carlo “walkers” for a 144 atom supercell. The results of this model are used to fit a Heisenburg
model to generate the density of magnetic states. To enhance the ability to measure the properties of
multiple materials, we have developed the capability for discovery of new MC alloys using
combinatorial sputtering. The combinatorial equipment has been designed, fabricated, and is in the
process of being installed. While the combinatorial equipment was being built, bulk alloys of
material were prepared for testing in experiments at the National High Magnetic Field Laboratory
and in ORNL’s 9 tesla superconducting magnet. These alloys were suggested by both our
computational modeling efforts and some that have been widely investigated as standards for
comparison, and some of the Ni 2 MnGa alloys included small amounts of iron and/or copper to
examine the effects of these elements on the structural and magnetic transition temperature. These
materials were characterized using differential scanning calorimeter (DSC) and superconducting
quantum interference device (SQUID) techniques. The results of testing the bulk alloy materials
demonstrated that it is possible to control the structural and magnetic transition temperatures using
small amounts of iron and copper and that it is possible to manipulate the Curie temperature using
these materials.
Information Shared
Nicholson, D. M., Kh. Odbadrakh, A. Rusanu, M. Eisenbach, G. Brown, and B. M. Evans III. 2010. “First
Principles Approach to the Magneto Caloric Effect: Application to Ni 2 MnGa.” Proceedings of the
55th Annual Conference on Magnetism and Magnetic Materials.
05840
Closing Technology Gaps with the Development of Advanced Fusion
Experimental Facilities
Arnold Lumsdaine
Project Description
The realization of commercially viable fusion power would essentially end the current societal problems
of energy supply (greenhouse gas emission, release of other pollutants, fuel importation from hostile
societies, nonrenewable supply, storage of long-term radioactive waste, risk of runaway reaction or
meltdown, risk of proliferation of nuclear materials, etc.). The continued international support for
research in fusion energy despite limited success in delivering on past promises is a testimony to its
remarkable possibilities. The ITER international experimental reactor will begin operation in the next
decade and will subsequently generate relatively long-pulse burning plasmas, producing up to 10 times
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