Quantum Chemical Methods and Pressure's Effect on Permalloy Permeability

Abstract

In a dynamic field along the magnetization hard and Easy axis, Permalloy nanoparticles (Ni81Fe19)1-x(Al2O3)x were deposited by RF sputtering on Corning glass substrates. With argon pressure ranges of 4.10-3 and 60.10-3, the samples were exposed to a magnetic field, resulting in Al2O3 substitution rates of 24, 34, and 44%. The permeability spectra calculated from the Gilbert Lifshitz Landau model are consistent with the data and damping coefficient inferred from this change. The damping ratio values are in agreement with the results from the earlier studies following this change. Similar to pressure, the damping coefficient augments linearly, and the Full Width at Half-Maximum values of the imaginary part of the permeability-dependent frequency exhibits a linear correlation with the depth coefficient. Fits used a convolution of Lorentzian (TMS, magnon-electron term) and Gaussian (inhomogeneity) linewidths. Py film FMR showed (4πM_s) increased with H_a, nearing theory. This work clarifies Gilbert damping in magnetic films for spintronic devices, sensor and photovoltaic applications.