Journal ArticleDOI
Inductive measurement of ultrafast magnetization dynamics in thin-film Permalloy
TLDR
In this article, an inductive technique for the measurement of dynamical magnetic processes in thin-film materials is described using 50 nm films of Permalloy (Ni81Fe19) and data are presented for impulse and step-response experiments with the applied field pulse oriented in the plane of the film and transverse to the anisotropy axis.Abstract:
An inductive technique for the measurement of dynamical magnetic processes in thin-film materials is described. The technique is demonstrated using 50 nm films of Permalloy (Ni81Fe19). Data are presented for impulse- and step-response experiments with the applied field pulse oriented in the plane of the film and transverse to the anisotropy axis. Rotation times as short as 200 ps and free oscillations of the magnetization after excitation are clearly observed. The oscillation frequency increases as the dc bias field parallel to the anisotropy axis increases as predicted by classical gyromagnetic theory. The data are fitted to the Landau–Lifshitz equation, and damping parameters are determined as a function of dc bias field. Damping for both impulse and step excitations exhibits a strong dependence on bias field. Damping for step excitations is characterized by an anomalous transient damping which rapidly increases at low dc bias field. Transformation of the data to the frequency domain reveals a higher order precessional mode which is also preferentially excited at low dc bias fields. A possible source for both phenomena is precessional mode saturation for large peak rotations. The technique has the potential for 20 ps resolution, although only 120 ps resolution is demonstrated due to the limited bandwidth of the waveguides used.read more
Citations
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Journal ArticleDOI
Coherent control in ferromagnets driven by microwave radiation and spin polarized current
TL;DR: In this paper, the effect of spin-polarized current on coherent control of a ferromagnetic system is studied and the role of magnetic anisotropy field is discussed.
Book ChapterDOI
Micromagnetics: Dynamical Aspects
TL;DR: In this article, an extension of Stoner and Wohlfarth's reversal model to the dynamic regime is presented, and the existence of “ballistic” trajectories is demonstrated.
Spin wave nonreciprocity for logic device
TL;DR: In this article, a spin wave Mach-Zehnder device was proposed based on the spin wave amplitude, utilizing the non-reciprocal spin wave behavior excited by microstrip antennas.
Journal ArticleDOI
Cryogenic pulsed inductive microwave magnetometer
TL;DR: In this article, a cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film magnetic materials at low temperatures and microwave frequencies. Butler et al. used a coplanar waveguide structure with the sample placed in a flip-chip configuration.
Book ChapterDOI
Carbon-Nanotube Reinforced Polymers
TL;DR: In this paper, the authors developed electromagnetic models for the inspection of carbon-nanotube reinforced polymers (CNRPs), along the lines of our work with CFRPs.
References
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Book
Introduction to solid state physics
TL;DR: In this paper, the Hartree-Fock Approximation of many-body techniques and the Electron Gas Polarons and Electron-phonon Interaction are discussed.
Journal ArticleDOI
A Mechanism of Magnetic Hysteresis in Heterogeneous Alloys
Edmund C. Stoner,E. P. Wohlfarth +1 more
TL;DR: In this paper, the effect of shape anisotropy on magnetization curves was studied for the case of ellipsoidal spheroids of revolution (e.g., ellipses of revolution).
Book
Theory of Magnetic Recording
TL;DR: This paper presents a simulation of the playback process of the magnetostatic fields of magnetoresistive heads, a very simple and straightforward way of cataloging the fields and their properties.
Book
Handbook of microwave integrated circuits
TL;DR: Hoffmann et al. as mentioned in this paper presented the Handbook of microwave integrated circuits (HOLA) for the purpose of measuring the pressure fields using covariance and spectral proper transformations.