Fe-Ga alloys of appropriate Ga concentration and heat treatment show a very large enhancement in the tetragonal magnetostriction over that of pure $\alpha \text{−}\mathrm{Fe}$ $[{\lambda }_{100}\left(\mathrm{Fe}\text{−}\mathrm{Ga}\right)\sim 15{\lambda }_{100}\left(\mathrm{Fe}\right)]$. In order to gain further understanding of the extraordinary magnetoelastic characteristics of this system, the spin dynamics of two of these alloys, ${\mathrm{Fe}}_{1-x}{\mathrm{Ga}}_x$ ($x=0.160$ and 0.225), were studied using inelastic neutron scattering techniques. The correlation of the spin-wave dispersion curve with the lattice constant and atomic radii of solute is examined for this and other Fe alloys.

• Received 16 November 2006

DOI:https://doi.org/10.1103/PhysRevB.75.052406