Fast Strain Wave Induced Magnetization Changes in Long Cobalt Bars: Domain Motion versus Coherent Rotation

Published

February 11, 2015

Author(s)

S. Davis, Julie Borchers, Brian B. Maranville, S. Adenwalla

Abstract

A fast (88 MHz) traveling strain wave on a piezoelectric substrate is shown to rapidly change the magnetization direction in 40 micron wide Co bars with an aspect ratio of 10³. The rapidly alternating strain wave rotates the magnetization away from the long easy axis into the short hard axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments werelimited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the traveling strain wave does rotate the magnetization away from the long easy axis direction. An investigation of the behavior of the hard axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation since the 88 MHz strain wave cannot move domain walls. The neutron reflectivity data are consistent with this interpretation.

Citation

Journal of Applied Physics

Volume

117

Issue

6

Pub Type

Journals

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Keywords

Surface acoustic wave, polarized neutron reflectivity, dynamic magnetization switching, coherent magnetization rotation

Citation

Davis, S. , Borchers, J. , Maranville, B. and Adenwalla, S. (2015), Fast Strain Wave Induced Magnetization Changes in Long Cobalt Bars: Domain Motion versus Coherent Rotation, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=915834 (Accessed October 18, 2025)