Effect of quenching on the magnetostriction on Fe1-xGa x (0.13x<0.21)

The magnetostriction (λ₁₀₀) of b.c.c. Fe is increased over 10-fold at room temperature by the substitution of ~20% gallium for Fe. Fe_1-xGa_x alloys with x between 0.19 and 0.214 that are quenched from 800°C exhibit magnetostrictions ~25% higher than those furnace-cooled at 10°/min. We propose that this great increase of magnetostriction above that of Fe in Fe-Ga alloys is not due to conventional magnetoelastic effects but due to the substitutive presence of asymmetrically shaped clusters of the Ga atoms. As the concentration of solute atoms approaches 25%, the lattice becomes relaxed with formation of a more ordered structure and the magnetostriction decreases in value