Full text loading...
Variation in anisotropy field , saturation magnetization , and easy axis coercivity with CoFeB content in the multilayer stack. is linearly increasing with CoFeB fraction , whereas is almost independent with and increases only slightly by 6%. The inset depicts quasistatic magnetic loops obtained from an extended CoFeB film, displaying clear easy and hard axis behavior.
The precessional frequency square and effective damping parameter as a function of the relative CoFeB content determined for the extended reference films. is increasing with CoFeB content and hence with . The damping parameter displays only a minor change with .
(a) Bias field dependence of for the structured Py and CoFeB films. From the permeability spectra of the square elements at (inset), the resonance frequency of the structured films of varying composition is deduced (b). The natural resonance frequency (at ) of the patterned samples displays neither a dependence on nor on the corresponding variation in the anisotropy field .
(a) The remanent domain states of elements with relative CoFeB contents , 0.5, and 1 after applying a saturating initialization field along the easy axes. Arrows indicate the general easy and hard axis magnetization directions in the domains. (b) A magnetization canting and modulated substructure is schematically marked by arrows inside the closure domains. Responding to a pulse field the macrospin precession in domain structures of different anisotropy creates dynamic magnetic charges concentrated at the closure domain walls.
Article metrics loading...