Magnetostrictive properties of body-centered cubic Fe-Ga and Fe-Ga-Al alloys

The magnetic and magnetostrictive properties of Fe1-xGax and Fe1-x-yGaxAly (x + y < 0.3) single crystals were measured under compressive stresses up t o 120 MPa and in magnetic fields up to 1 kOe. Values of <lambda>(100) excee ding 200 ppm were observed in samples of Fe83Ga17 from 180 K to room temper ature. Only a small monotonic decrease in magnetostriction with temperature was found. On the other hand, lambda (111) maintained small negative value s close to those of b.c.c. Fe. In all cases, no higher order magnetostricti ve terms were detectable. With 15 to 20 atomic percent replacement of Fe by Ga, the magnetizations remain high (M-s congruent to 1.8 T) and the magnet ic anisotropies reduced (K-1 congruent to 10(4) J/m(3)). Values of the 'sti ff' (high magnetic field) Young's modulus, Bulk modulus, Poison's ratio, an d elastic constant c(11)-c(12) for Fe85Ga15 at room temperature are, respec tively, 77 GPa, 111 GPa, 0.38, and 56 GPa.