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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Spin wave contributions to the high-frequency magnetic response of thin films obtained with inductive methods
TL;DR: In this paper, the high-frequency magnetic response of Permalloy thin films has been measured using network-analyzer ferromagnetic resonance, and it has been shown that the excitation of spin waves by the coplanar wave-guide modify the magnetic response appreciably, in particular, by causing a frequency shift and broadening of the resonance peak.
Journal ArticleDOI
Approaching soft X-ray wavelengths in nanomagnet-based microwave technology
Haiming Yu,Haiming Yu,O. d’ Allivy Kelly,Vincent Cros,R. Bernard,P. Bortolotti,Abdelmadjid Anane,Florian Brandl,F. Heimbach,Dirk Grundler,Dirk Grundler +10 more
TL;DR: This work demonstrates magnonic devices at wavelengths of 88 nm written/read by conventional coplanar waveguides and shows how microwave-to-magnon transducers are reconfigurable and thereby provide additional functionalities, paving the way for a multi-functional GHz technology with unprecedented miniaturization exploiting nanoscale wavelengths that are otherwise relevant for soft X-rays.
Journal ArticleDOI
Broadband stripline ferromagnetic resonance spectroscopy of ferromagnetic films, multilayers and nanostructures
TL;DR: In this paper, the authors present a comprehensive critical overview of fundamental and practical aspects of the modern stripline broadband ferromagnetic resonance (BFMR) spectroscopy largely employed for the characterisation of magnetic low-dimensional systems.
Journal ArticleDOI
Precessional switching of submicrometer spin valves
Shehzaad Kaka,Stephen E. Russek +1 more
TL;DR: In this article, small spin valves are switched using a subnanosecond field pulse applied along the magnetization hard axis, which indicates a large-angle precessional motion in response to the transverse applied field.
Journal ArticleDOI
Classical model of extrinsic ferromagnetic resonance linewidth in ultrathin films
R.D. McMichael,P. Krivosik +1 more
TL;DR: In this article, a classical version of the two-magnon model of ferromagnetic resonance linewidth in inhomogeneous magnetic thin films is described in terms of film properties and the statistical properties of the inhomogeneity.
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