William E. Bailey

Control of magnetization dynamics in Ni/sub 81/Fe/sub 19/ thin films through the use of rare-earth dopants

We show that the magnetization dynamics of soft ferromagnetic thin films can be tuned using rare-earth (RE) dopants. Low concentrations (2 to 10%) of Tb in 50 nm Ni/sub 81/Fe/sub 19/ films are found to increase the Gilbert magnetic damping parameter /spl alpha/ over two orders of magnitude without great effect on easy axis coercivity or saturation magnetization. Comparison with Gd dopants indicates that the orbital character of the Tb moment is important for transferring magnetic energy to the lattice. Structural transformations from the crystalline to the amorphous state, observed over the first 2%-10% of RE doping, may play a contributing but not sufficient role in damping in these films. The approach demonstrated here shows promise for adjusting the dynamical response, from underdamped to critically damped, in thin film materials for magnetic devices.

Dopants for independent control of precessional frequency and damping in Ni81Fe19 (50 nm) thin films

Dilute impurities can be used to control the dynamical response of ferromagnetic thin film magnetization at frequencies >1 GHz. Central lanthanide dopants (Sm, Eu, Tb, Dy, and Ho) have been investigated for their effect on the magnetization dynamics of Ni81Fe19 (50 nm). We find that Sm, Dy, and Ho contribute an increase on damping α up to four times stronger per concentration than that provided by Tb, with minimal effect on precessional frequency. One dopant, Eu, leaves α unchanged but boosts the resonant frequency fp of the system by ∼500 MHz for 3% addition, equivalent to a dynamic anisotropy field of 9 Oe, “stiffening” the system. The results indicate that precessional frequency and damping may be controlled independently in magnetoelectronic device materials.

Low relaxation rate in epitaxial vanadium-doped ultrathin iron films

The longest relaxation time and sharpest frequency content in ferromagnetic precession is determined by the intrinsic (Gilbert) relaxation rate \emph{

Precessional dynamics of elemental moments in a ferromagnetic alloy

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Magnetostriction and angular dependence of ferromagnetic resonance linewidth in Tb-doped Ni0.8Fe0.2 thin films

}. For many years, pure iron (Fe) has had the lowest known value of

Structural comparisons of ion beam and dc magnetron sputtered spin valves by high‐resolution transmission electron microscopy

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Design of coupled power inductors with crossed anisotropy magnetic core for integrated power conversion

for all pure ferromagnetic metals or binary alloys. We show that an epitaxial iron alloy with vanadium (V) possesses values of

Weakly coupled motion of individual layers in ferromagnetic resonance

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A compact apparatus for studies of element and phase-resolved ferromagnetic resonance

which are significantly reduced, to 35

Spin pumping damping and magnetic proximity effect in Pd and Pt spin-sink layers

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