Static and Microwave Properties of Amorphous Magnets Near Saturation

Abstract

Static and dynamic properties of magnetically soft amorphous ferromagnets have been studied analytically and numerically within random-field and random-anisotropy models. External field and coherent anisotropy that are weak compared to their random counterparts are sufficient to bring the magnet close to saturation. The scaling of spin-spin correlations in this regime is computed, and its dependence on parameters is confirmed by Monte Carlo simulation. We show that near the ferromagnetic resonance, the spin excitations are damped and spatially localized due to randomness even close to saturation. On increasing the strength of randomness, the localization length goes down in accordance with theoretical expectations, while the damping of spin excitations goes up.

arXiv comment10 PR pages, 6 figure captions

References in corpus (21)

• Magnetic resonance studies of the fundamental spin-wave modes in individual submicron Cu/NiFe/Cu perpendicularly magnetized disks
• Random Field XY Model in Three Dimensions
• Bose glass transition and spin-wave localization for 2D bosons in a random potential
• Magnetization reversal via internal spin waves in magnetic nanoparticles
• New approach to designing functional materials for stealth technology: Radar experiment with bilayer absorbers and optimization of the reflection loss
• Disordered Boson Systems: A Perturbative Study
• Spin-wave localization in disordered magnets
• Experimental and Numerical Understanding of Localized Spin Wave Mode Behavior in Broadly Tunable Spatially Complex Magnetic Configurations
• Power-law correlations and orientational glass in random-field Heisenberg models
• Random Field and Random Anisotropy Effects in Defect-Free Three-Dimensional XY Models
• Topological order generated by random field in a 2D exchange model
• Absorption of Microwaves by Random-Anisotropy Magnets
• Localization of disordered bosons and magnets in random fields
• Scaling of Coercivity in a 3d Random Anisotropy Model
• Structure Factor of the 3D Random Field XY Model
• Nonlinear and Thermal Effects in the Absorption of Microwaves by Random Magnets
• Random Anisotropy Magnet at Finite Temperature
• Ordered vs Disordered States of the Random-Field Model in Three Dimensions
• Integral Absorption of Microwave Power by Random-Anisotropy Magnets
• Localized Spin-Wave Modes and Microwave Absorption in Random-Anisotropy Ferromagnets
• Scaling of Static and Dynamical Properties of Random Anisotropy Magnets