Direct and inverse measurement of thin films magnetostriction

TL;DR

This paper compares direct and inverse techniques for measuring thin film magnetostriction, analyzing how substrate properties and bending conditions affect measurement accuracy and providing equations for practical magnetostriction determination.

Contribution

It introduces a comparative analysis of direct and inverse magnetostriction measurement methods and derives equations for accurate magnetostriction evaluation considering substrate effects.

Findings

Both measurement methods are influenced by substrate elastic strength.

Magneto-mechanical coupling varies with bending conditions.

Provided equations improve magnetostriction measurement accuracy.

Abstract

Two techniques of measurements of thin film magnetostriction are compared: direct, when changes of the substrate curvature caused by the film magnetization are controlled, and inverse ("indirect"), when the modification of the magnetic anisotropy induced by the substrate deformation (usually bending) is measured. We demonstrate how both the elastic strength of the substrate and the effective magneto-mechanical coupling between the substrate deformation and magnetic anisotropy of the film depend on different conditions of bending. Equations to be used for magnetostriction value determination in typical cases are given and critical parameters for the corresponding approximations are identified.