Mannan Ali
Journal of Magnetism and Magnetic Materials 202 (1999) 85-94
Measurement Of Saturation Magnetostriction Using Novel Strained Substrate Techniques
And The Control Of The Magnetic Anisotropy
M. Ali, R. Watts
Department of Physics, University of Sheffield, Sheffield S3 7RH, UK
Abstract
A simple new technique is described for the measurement of saturation magnetostriction in thin
films deposited onto rigid substrates. The method is based on mechanically introducing a small
curvature in the substrate either during the deposition (strained growth) or post-deposition.
The strain induced anisotropy is measured using the magneto-optical Kerr effect. Quantification
of the film strain is obtained using optical interference and stylus measurements; coupled with
mechanical finite element modelling, this allows the saturation magnetostriction to be determined.
No information about the mechanical properties of the substrate is required, and providing that the
Young’s modulus of the film is known accurately, the values of magnetostriction obtained are accurate
and absolute. It is envisaged that the technique could be applied to a wide variety of films deposited
onto commercially important substrates. Here, it is applied to amorphous films based on the METGLAS
2605SC composition deposited on to glass and silicon substrates. A high degree of control is also
demonstrated in tailoring the anisotropy field, by the technique of substrate straining.
More information and related data will be added here soon.
ERRATUM
Equation (1) in the paper should be modified by a factor depending on
Poisson’s ratio (vf) of the film.
