Magnetic Crystal Anisotropy and Magnetostriction of Iron-Nickel Alloys

Single crystals of a number of iron-nickel alloys were prepared, and measurements made of the magnetic crystal anisotropy, and of the magnetostriction at saturation in different crystallographic directions, as dependent on the rate of cooling of the specimens after annealing. There is a large effect of the cooling rate on the anisotropy, for compositions near Fe${\mathrm{Ni}}_3$, where atomic ordering occurs. There is a definite but smaller effect of cooling rate on the magnetostriction. The composition for highest initial and maximum permeabilities is nearly that for which ${\lambda }_{111}$, the magnetostriction in the direction of easy magnetization, is equal to zero.