The effective magnetostriction (λs) of ultrathin CoFe sensor layers has been measured as a function of CoFe and spin-filter nonmagnetic layers over the range from 1.0 to 3.0 nm. The λs shows an anomalous variation at thicknesses of interest and disagrees with the expectation of the Néel model, where the surface/interface contribution is supposed to lead to observation that the λs varies with the well-known reciprocal law of magnetic layer thickness. Within the framework of a coherent strain model proposed herewith, both the deviation of magnetostriction behavior from the reciprocal law and its nonmagnetic layer structure dependence are satisfactorily explained. The interface-induced magnetoelastic coupling, laminated structure dependent strains, and stresses are called for in explaining the magnetostriction of magnetically soft sensor layers.
- Giant magnetoresistance
- Magnetic recording/spin valves head
- Magnetic thin films
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering