Optimization of Co-P Multilayer Thickness for the Magnetoelastic Response

The amplitude of resonant magnetoelsatic waves propagating along Co-P multilayers is experimentally investigated as a function of the thickness of magnetic and non-magnetic component layers. A giant amplitude is obtained because the stress sensitivity can be diminished without decreasing the macroscopic permeability, but it is shown that the layer thickness must be optimized in order to have the maximum wave amplitude. At a fixed frequency, both experimental results and theoretical considerations demonstrate that the optimal thickness of each magnetic layer is influenced by skin depth, while the corresponding best value for the non-magnetic layers depends on both the exchange coupling through magnetic layers and the condition of minimum stress sensitivity.