50th Annual Conference on Magnetism and Magnetic Materials
San Jose, CA
Body centered cubic Fe1−xBex alloys are known to display an enhanced tetragonal magnetostriction compared to Fe. In order to characterize the enhanced magnetoelasticity observed in this alloy system, we present detailed inelastic neutron scattering measurements of the phonon dispersion relations of a single crystal of bcc Fe, 10 at. %Be along the high symmetry directions , , and  at room temperature. We observe in particular that the frequency of transverse phonons propagating along the  direction with a  polarization at the zone boundary is reduced by 10% with respect to bcc Fe (the corresponding elastic shear constant c′ = ½(c11−c12) associated with this mode is approximately 70% that of pure Fe). The dispersion of spin waves has also been determined for energy transfers up to 40 meV and is found to follow the isotropic dispersion relation E(q) = Dq2, with D ∼ 200 meV/Å2 [for Fe, E(q) = Dq2, with D = 280 meV/Å2].
American Institute of Physics
Zhao, P.; Cullen, J.; Wuttig, M.; Kang, H. J.; Lynn, J. W.; Lograsso, Thomas A.; and Moze, O., "Lattice and spin dynamics in bcc Fe, 10 at. % Be" (2006). Ames Laboratory Conference Papers, Posters, and Presentations. 19.