Measuring the magnetostriction of thin films using an optical displacement meter

Abstract

Using a commercially available optical displacement meter, the deflection caused by magnetostriction is measured. A displacement sensitivity of 0.1 mu m enables magnetostriction as low as 4*10-7 to be measured in a 1 mu m thick film. Two different probes are used to measure deflection when an applied magnetic field is rotated in the film plane and when rotated in a plane perpendicular to the film. Two parameters, lambda 100 and lambda 111, can be obtained from measurements using two probes. The measured value of the Ni film showed agreement with reported bulk values within 10%.