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.