A Brillouin light scattering study and theoretical interpretation of spin-wave modes in arrays in-plane magnetized micron-size rectangular ${\mathrm{Ni}}_{80}{\mathrm{Fe}}_{20}$ elements are reported. It is shown that two-dimensional eigenmodes these can be approximately described as products one-dimensional longitudinally transversely long finite-width permalloy stripes. The lowest dipole-exchange nature localized near the element edges, while higher a mostly dipolar weakly center....

We have observed collective spin-wave modes in inhomogeneously magnetized ${\mathrm{Ni}}_{0.81}{\mathrm{Fe}}_{0.19}$ thin-film stripes. The stripes, 18 nm thick and $2\ensuremath{\mu}\mathrm{m}$ wide, are studied an in-plane magnetic field oriented along their short axes. When the is on order of shape anisotropy field, equilibrium magnetization near stripe edges rotates 90 deg over a length scale $100\mathrm{nm}--1\ensuremath{\mu}\mathrm{m}.$ Time-resolved Kerr microscopy used to detect...

We have observed several localized modes in the spin-wave spectrum of a permalloy microstripe (length 90 μm, width 1 thickness 0.033 μm) magnetized along its width. The mode frequencies increase from 4.5 to 8 GHz with increasing applied field (0–1.1 kOe). These are interpreted as multiple spin–wave eigenstates effective potential wells created by strongly inhomogeneous internal magnetic stripe near edges.

The magnetic field dependences of the frequencies standing spin-wave modes in a tangentially magnetized array thin rectangular permalloy dots (800 × 550 nm) were measured experimentally by Brillouin light scattering technique and calculated theoretically using an approximate size-dependent quantization spin-wavevector components dipole-exchange dispersion equation for spin waves propagating continuous film. It was found that inhomogeneous internal bias dot has strong influence on profiles...

We describe a spin wave traveling through 180/spl deg/ Bloch-domain wall. The resulting linearized Bloch equations have the same form as for propagating past negative effective field well. varies slowly relative to wavelength of considered waves. A Wentzel-Kramers-Brillouin (WKB) approximation is used estimate phase shift and compared known exact results.

The manipulation of the antiferromagnetic interlayer coupling in epitaxial $\mathrm{F}\mathrm{e}/\mathrm{C}\mathrm{r}/\mathrm{F}\mathrm{e}(001)$ trilayers by 5 keV He ion beam irradiation has been investigated. It is shown that even for with low fluences a drastic change strength appears. For thin Cr spacers (below 0.6--0.7 nm) it decreases fluence, becoming ferromagnetic above $2\ifmmode\times\else\texttimes\fi{}{10}^{14}\text{...

Systems for process automation become increasingly complex and also tend to be composed of autonomous subsystems, which is strongly driven by the progress made in information technology. An active field research implementation monitoring control at sub-system level using cognitive approaches. In this paper we present a method sensorless condition an electric drive train. Based on experiment design measured phase currents physical demonstrator device including mechanical defects extracted...

In this paper we present a laser sensor for highly spatially resolved flow imaging without using camera. The is an extension of the principle Doppler anemometry (LDA). Instead parallel fringe system, diverging and converging fringes are employed. This method facilitates determination tracer particle position within measurement volume leads to increased spatial velocity resolution compared conventional LDA. Using total number four systems in two dimensions orthogonal component. Since no...

We calculate semianalytically the spin-wave eigenmodes and frequencies of an infinite thin film with periodically modulated exchange bias field. show that both localized propagating modes exist in this system band gaps at edges Brillouin zone. The can be tailored by changing period superlattice. This method is technological relevance as modification spectrum achieved without any change topography.

We present micromagnetic simulations of the spin-wave spectra in Landau domain patterns. Ultrashort field pulses various spatial symmetries are used to excite distinct eigenmodes. The frequencies as well symmetry mode patterns depend on exciting torque. latter is determined by pulse and magnetic ground state. have collective excitations, i.e., modes cannot be considered for each individually. find transversal longitudinal observed experimentally. From profiles an effective dispersion...

For the investigation of turbulent flows, measurement Lagrangian acceleration is great interest as it represents a direct component Navier–Stokes equations. The presented sensor based on common laser Doppler technique, but offers in addition combined high spatial resolution micrometre range and possibility measuring velocity along optical axis. As result setup, signals particles with inclined trajectories show frequency modulation within single burst similar to signal an accelerated...

This paper presents the development of a diagnostic method which uses measurement motor currents in order to detect defects electromechanical systems. It focusses on two main topics: acquisition experimental data, and method. The data was crucial for successful dedicated signal analysis For this purpose, test rig generating training created. provides ability simulate wide range experimentally. Different types artificial defects, such as bearing damage or misalignments, were used; these are...

The vigilant observation of medical devices during post-market surveillance (PMS) for identifying safety-relevant incidents is a non-trivial task. A wide range sources has to be monitored in order integrate all accessible data about the safety and performance device. PMS needs supported by an efficient search strategy possibility create complex queries domain experts. We use ontologies support specification preparation document corpus, which contains relevant documents. In this paper, we...

Design of micro systems, MEMS or mechatronic systems is dominated by the interaction effects from different physical domains. One important approach to decrease number design cycles significantly system level modeling and simulation. The main challenges for efficient use simulation are a systematic behavioral modeling, automated model generation as well powerful frameworks. Especially latter flexible handling models computation crucial.

Reliability of machines and facilities has played an important role since many years.Nowadays, attention is also paid to maintenance times.Maintenance standstills are be reduced as far possible.On the other hand, technical systems subject signs wear tear which in general growing slowly imperceptibly.The gradual abrasion applied tools may lead poor production tolerances or a component's standstill.Hence, condition-based strategy will increasing importance.Such requires permanent condition...

A writing scheme is presented for Savtchenko-type magnetic random access memory (MRAM) cells, which allows ultrafast direct with high stability against half select switching, using two orthogonally oriented unipolar field pulses time delay, backswitching by reversing the temporal sequence of pulses. The numerical simulations are based on Stoner–Wohlfarth model and a Runge Kutta integration Landau–Lifshitz Gilbert equation.

The permittivity of a ferroelectric n-type semiconductor varies smoothly with depth beneath reversed biased Schottky contact. In partially depleted films, the depletion layer controls capacitance. fully films inverse capacitance is proportional to thickness, which suggests that effects do not cause dead-layer behavior.

Excitation spectrum of homogeneously magnetized Ni/sub 80/Fe/sub 20/ rectangles using Brillouin light scattering (BLS) is reported. A model to qualitatively describe the spin-wave presented and its results compared with both experiment micromagnetic simulations. Micromagnetic simulation show that internal field inhomogeneous along direction applied field. It was concluded spin wave modes can be approximately described as a linear combination longitudinally stripe transversely stripe.

We investigate photonic crystal waveguides that are formed by holes of reduced diameter within a hexagonal lattice cylindrical airholes in thin freestanding silicon slabs. The operate both an even-symmetry bandgap and partial gap odd-symmetry modes form complete two-dimensional under the light line. operating frequency is tuned small-hole to fit range bandgaps match free-space wavelength 1550 nm. Their narrow bandwidth low group velocity propagation renders useful as filters or sensing...

Often; mathematical models with different levels of detail are used. In this contribution; a model drum motor is presented. This was designed for the description dynamic behaviour as well possible implementation several wearing phenomena. Using model; better understanding wear and tear phenomena has been achieved by carrying out considerable number simulation runs using operational conditions. information; important knowledge about detection wearout signs able to be gained.

Es werden ein auf der Laser-Doppler-Anemometrie basierender neuartiger interferometrischer Sensor und entsprechende Konzepte zur Signalverarbeitung vorgestellt. Der ermöglicht es, entlang einer Linie das Geschwindigkeitsprofil von Strömungen mit Ortsauflösung bis in den Sub-Mikrometerbereich zu vermessen eignet sich deshalb besonders für Turbulenzforschung, Mikrofluidik Durchflussmessungen. Die Kombination zweier solcher Sensoren erlaubt die Bestimmung drei Geschwindigkeitskomponenten...