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Full-Text Articles in Physics
Normal Mode Mixing And Ferromagnetic Resonance Linewidth, Andrew Kunz, R. D. Mcmichael
Normal Mode Mixing And Ferromagnetic Resonance Linewidth, Andrew Kunz, R. D. Mcmichael
Physics Faculty Research and Publications
The normal modes of an inhomogeneous thin film are obtained by diagonalization of the perturbed Hamiltonian. The resulting modes are mixtures of the spin-wave modes and the uniform mode. We find that the ferromagnetic resonance intensity spectrum of the diagonalized system has a Lorentzian profile, and that the results correspond to the two-magnon model for weak perturbations. For stronger perturbations, the density of states is smoothed, and the spectrum becomes asymmetric due to the low-frequency cutoff of the spin-wave manifold. The technique is expected to be valid for perturbation amplitudes that are large enough to invalidate the assumptions of the …
Calculation Of Damping Rates In Thin Inhomogeneous Ferromagnetic Films Due To Coupling To Lattice Vibrations, R. D. Mcmichael, Andrew Kunz
Calculation Of Damping Rates In Thin Inhomogeneous Ferromagnetic Films Due To Coupling To Lattice Vibrations, R. D. Mcmichael, Andrew Kunz
Physics Faculty Research and Publications
This article describes calculations of ferromagnetic resonance damping rates due to coupling between the magnetization and lattice vibrations through inhomogeneities. The mechanisms we have explored include generation of shear phonons through inhomogeneous anisotropy and generation of both longitudinal and shear phonons through inhomogeneous magnetostriction. In both cases, inhomogeneities couple the uniform precession to finite wave vector phonons. For both coupling mechanisms, the predicted damping rate is on the order of 106 s-21 in transition metals. The damping rate by these mechanisms is inversely proportional to the fifth power of the shear phonon velocity, and may play a significant …
Epr Of Co(Ii) As A Structural And Mechanistic Probe Of Metalloprotein Active Sites: A Review Of Studies On Aminopeptidase, Brian Bennett
Epr Of Co(Ii) As A Structural And Mechanistic Probe Of Metalloprotein Active Sites: A Review Of Studies On Aminopeptidase, Brian Bennett
Physics Faculty Research and Publications
Co(II) can often be substituted for Zn(II) in zinc-dependent metalloenzymes to provide spectroscopically accessible forms of the enzymes. Co(II) is an excellent spectroscopic probe as it is both optically active and EPR active. Further, its fast relaxation properties make it a useful paramagnetic shift reagent in NMR. In EPR, the dependence of the spectra of high-spin Co(II) on E/D and the sensitivity of the resolvability of the 59Co hyperfine structure to strain terms allow structural information to be inferred from the EPR spectra. In addition to its useful spectroscopic properties, Co(II) is often an extremely good functional mimic of …