A new high-precision optical technique to measure magnetostriction of a thin magnetic film deposited on a substrate

The drive in data storage technology towards utilizing magnetic films with lower magnetostriction (to reduce the magnetoelastic energy term) and reduced thickness has resulted in the requirement for more sensitive, reliable, and easy-to-use tools to monitor magnetostriction. A measurement tool based on an in-plane rotating and saturating magnetic field and laser-beam-deflection technique, which is able to meet these requirements, is described. The tool developed offers high accuracy, large dynamic range, long-term stability, simple sample insertion, and a fast, easy measurement procedure. With this tool, the measurement of small magnetostriction coefficients of thin soft-magnetic films can become a simple, fast, and reliable procedure, thus helping the development of magnetic thin-film production processes and routine composition control