CHECKING METHOD OF MAGNETOSTRICTION CONSTANT OF MAGNETIC FILM WITH UNIAXIAL ANISOTROPY

摘要

PURPOSE:To detect a magnetostriction constant by measuring the anisotropic magnetic field of an uniaxially magnetic anisotropic film with an easy magnetization axis in a film surface formed on a substrate when the film is strained and when not. CONSTITUTION:A current (i) is flowed in the direction of the easy magnetization axis of the uniaxially magnetic anisotropic film 2 formed on the substrate 1 to apply a magnetic field 6 in the direction of the hard magnetization axis. The intensity of an anisotropic magnetic field is found from the current resistance value and intensity of the applied magnetic field. Then, a load P is placed on the substrate 1 while knife-edges 71 and 71' are regarded as fulcrums and 72 and 72' are regarded as loading points. Then, the substrate surface is applied with uniform tensile stress sigma in the current direction. At this time, the anisotropic magnetic field HK is measured. Consequently, a magnetostriction constant lambda is found from an equation, wherein IS is saturated magnetism and mu is the Poisson's ratio.