Sur la dispersion de l'anisotropie et de la stabilité dans le temps des couches électrolytiques de Ni-Fe-Mo avec anisotropie biaxiale

The angular and amplitude dispersions of the anisotropy in Ni-Fe-Mo films with biaxial anisotropy have been studied. The permalloy films had a thickness of 5000 Å and those of permalloy with 5% Mo a thickness of 5400 å. The films were deposited onto plane copper substrates. The angular and amplitude dispersions, measured by the resonance absorption method, decrease with an increase in the angle between the anisotropy axes, having values of 4° and 2.8 Oe, respectively, for the permalloy films with an angle of 5° between the axes, and 2° 30′ and 2 Oe for films with an angle of 22° between the axes. For the permalloy films with Mo the dispersions decrease from 7° 30′ and 3.2 Oe to 6° 30′ and 2.9 Oe for an increase of the angle between the anisotropy axes from 10° to 20°.

The time variation (over 1000 h) of the angle between the anisotropy axes is given. Decreases from 22° to 17° and from 10° to 7° respectively for permalloy and permalloy with 5% Mo are obtained.