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
Dynamic and static magnetic anisotropy in thin-film cobalt zirconium tantalum
TL;DR: In this article, the magnetic anisotropy values of thin amorphous cobalt zirconium tantalum (CZT) films were determined from static and dynamic measurements.
Journal ArticleDOI
Influence of Sample Geometry on Inductive Damping Measurement Methods
Niklas Liebing,Santiago Serrano-Guisan,A. Caprile,E.S. Olivetti,Federica Celegato,Massimo Pasquale,A. Muller,Hans Werner Schumacher +7 more
TL;DR: In this paper, the authors study the precession frequency and effective damping of patterned permalloy thin films of different geometry using integrated inductive test structures, which consist of coplanar wave guides fabricated onto patterned percolation stripes of different geometries.
Journal ArticleDOI
Dynamics of spintronic materials: Exploration in the time and frequency domain
TL;DR: In this paper, the authors proposed two methods: polarized neutron reflectivity from magnetic films in an alternating magnetic field and time resolved resonant magnetic x-ray reflectivity of the free precessional dynamics in films and multilayers.
Book ChapterDOI
Introduction to Micromagnetic Recording Physics
Jan van Ek,Martin Plumer +1 more
TL;DR: In this paper, the authors provide an elementary introduction to magnetostatics, leading up to popular implementations of the micromagnetic method, as well as some of its shortcomings, and provide a background to many of the concepts discussed in the subsequent chapters.
Journal ArticleDOI
A spin-wave magnetometer with a positive feedback
Michael Balinskiy,Howard Chiang,A. V. Kozhevnikov,Y. A. Filimonov,Y. A. Filimonov,Alexander A. Balandin,Alexander Khitun +6 more
TL;DR: In this paper, the authors demonstrate the operation of a spin-wave magnetometer integrated into a circuit with a positive feedback and demonstrate that spin wave magnetometers can potentially be as sensitive as SQUIDs while operating at room temperature.
References
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