Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Magnetism in solid [sup 3]He

Thesis/Dissertation ·
OSTI ID:7112165

The magnetic properties of solid [sup 3]He have been studied using a first principle multiple exchange Hamiltonian. Within mean field approximation, the analytic expression for the free energy of the Hamiltonian has been derived for a variety of different magnetic phases. The effective spin wave Hamiltonian has been derived to determine the ground state and low temperature properties of solid [sup 3]He by application of an algebraic technique from nuclear theory (RPA). The very significant quantum corrections to the mean field ground state energy have been obtained in this approximation. From the calculated spin wave spectra, the specific heats of CNAF and UUDD solid [sup 3]He at low temperatures have been determined. An exactly solvable finite model related to the magnetism of solid [sup 3]He has been studied using group theory and the Gaussian ensemble. A variational technique combining the Peierls inequality with a classical Monte Carlo method has been developed for the quantum spin system. The tricritical point along the CNAF and the paramagnetic boundary has been predicted from the calculation and confirmed by a recent experiment. The interaction of hydrogen with bulk Pd and the Pd(110) surface has been studied using the first principles Density Functional Theory. The authors determined the equilibrium geometry, interaction potential and electronic structure of H in bulk Pd. The authors also determined the preferential adsorption sites, bond lengths, and vibration frequencies of H adsorbed on Pd. H-induced softening of the Pd surface phonon frequencies appears to be related to a corresponding softening of Pd-Pd interactions in the bulk hydride phase. The change in the substrate structure of Pd(110) (surface relaxation and reconstruction) due to the adsorption of hydrogen atoms was studied. A mechanism is suggested for the hydrogen induced 1 [times] 2 reconstruction of Pd(110).

Research Organization:
Michigan State Univ., East Lansing, MI (United States)
OSTI ID:
7112165
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English