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Selected Works

Carmine Vittoria

Ferromagnets

Articles 1 - 3 of 3

Full-Text Articles in Electromagnetics and Photonics

Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava Apr 2012

Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava

Carmine Vittoria

The phenomenological equations of motion for the relaxation of ordered phases of magnetized and polarized crystal phases can be developed in close analogy with one another. For the case of magnetized systems, the driving magnetic field intensity toward relaxation was developed by Gilbert. For the case of polarized systems, the driving electric field intensity toward relaxation was developed by Khalatnikov. The transport times for relaxation into thermal equilibrium can be attributed to viscous sound wave damping via magnetostriction for the magnetic case and electrostriction for the polarization case.


Relaxation Mechanism For Ordered Magnetic Materials, C. Vittoria, S. D. Yoon, A. Widom Apr 2012

Relaxation Mechanism For Ordered Magnetic Materials, C. Vittoria, S. D. Yoon, A. Widom

Carmine Vittoria

We have formulated a relaxation mechanism for ferrites and ferromagnets (insulators and metals) whereby the coupling between the magnetic motion and lattice is based purely on continuum arguments concerning magnetostriction. This theoretical approach contrasts with previous mechanisms based on microscopic formulations of spin-phonon interactions employing a discrete lattice. Our model explains the scaling of the intrinsic ferromagnetic resonance linewidth with frequency, with temperature { ∝1/Ms(T)} and the anisotropic nature of magnetic relaxation in ordered magnetic materials. Here, Ms(T) is the thermal saturation magnetization. Without introducing adjustable parameters, our model is in reasonable quantitative agreement with experimental measurements of the intrinsic …


Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava Jun 2011

Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava

Carmine Vittoria

The phenomenological equations of motion for the relaxation of ordered phases of magnetized and polarized crystal phases can be developed in close analogy with one another. For the case of magnetized systems, the driving magnetic field intensity toward relaxation was developed by Gilbert. For the case of polarized systems, the driving electric field intensity toward relaxation was developed by Khalatnikov. The transport times for relaxation into thermal equilibrium can be attributed to viscous sound wave damping via magnetostriction for the magnetic case and electrostriction for the polarization case.