Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"domain wall motion"”.
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THE STUDY OF PERPENDICULARLY MAGNETIZED COFE/PD MULTILAYERS FOR DOMAIN WALL MOTION
We focus the studies of DW motion in a CoFe/Pd multilayer-based nanowire with strong PMA. We find that high PMA, low saturation magnetization, narrow DW width and high spin polarization can induce low threshold current density for DW motion in CoFe/Pd superlattice-like multilayer films. Next, we …
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Magnetic domain walls driven by interfacial phenomena
A domain wall in a ferromagnetic material is a boundary between differently magnetized regions, and its motion provides a convenient scheme to control the magnetization state of the material. Domain walls can be confined and moved along nanostrips of magnetic thin films, which are proposed …
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Dzyaloshinskii-Moriya Interaction and Local Exchange Variation in Rare-Earth Transition-Metal Ferrimagnets
… memory storage. These technologies rely on the motion of chiral spin textures such as domain walls or skyrmions in order to read and write data. Rare-earth (RE) transition-metal (TM) ferrimagnetic heterostructures are especially promising candidates due to their minimal stray fields and …
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Magnetic Microstructure and Actuation Dynamics of NiMnGa Magnetic Shape Memory Materials
… actuators, displacement/force sensors, and motion dampers. Due to the huge strain and the magnetic field-driven nature, MSM materials show definite advantages over other smart materials, e.g. conventional thermal shape memory materials, in terms of displacement and speed. The principle …
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Modulation Technique for Magneto -Optic Imaging of Weak Magnetic Fields With Rare-Earth Iron Garnet Films
… system is limited by intrinsic film noise due to domain wall motion.
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DETECTION OF MAGNETIZATION REVERSAL IN A NEODYMIUM-IRON-BORON MAGNET USING A HALL-EFFECT MICROPROBE
… Barkhausen steps, indicating rapid domain wall motion, were observed (superimposed upon the blank probe signal) in the demagnetization of a fully magnetized magnet. Magnetization traces for a thermally demagnetized Nd-Fe-B magnet did not exhibit measurable Barkhausen steps until a …
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Probing the Behaviour of Antiferromagnets: Electric and Magnetic Measurements Across a Range of Length-scales
… are obtained, but the reported theory of domain wall motion within this class of compounds could not explain the observed behaviour. It was instead necessary to consider a combination of spin flop transitions and domain wall motion, demonstrating a lack of homogeneity which had been …
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Microstructural dynamics induced by nanoscale stress in ferroelectrics
… such as ferroelectric switching behaviour and domain wall motion. Intuitively, electric fields have been extensively used to probe and provide insight into these dynamics. Some studies have also investigated the role of mechanical stress on ferroelectrics, and with the advent of atomic force …
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Domain Wall Based Magnonics in Iron Garnet
… in thin films. Furthermore, relativistic domain wall velocities reported in yttrium iron garnet (YIG), bismuth substituted YIG, and thulium iron garnet lay the foundations for high-speed operation. These unique attributes position garnets as ideal materials for the development of magnonic …
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Sweeprate and Temperature Effects on Crackling Noise
… range of length and energy scales from jerky domain wall motion of disordered magnets, to the sometimes devastating crackling of the earth to the bursty release of energy in the photosphere of the sun dwarfing that of our most horrible WMD. Typically, crackling noise is modeled in the …
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Harnessing Magnetic Switching and Dynamics Using Electron and Magnon Spin Currents
… current. In the third work, we used magnetic domain walls to manipulate the phase and magnitude of a coherent spin wave, and in turn, investigated the domain wall motion driven by a spin wave. This mutual control can pave the way towards all-magnon computing devices. In the fourth work, we …
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Phase transitions and vortex dynamics in superconducting island arrays
… island arrays as a platform for studying vortex motion and quantum phase transitions. We investigate superconducting vortex dynamics and lattice structures in superconducting arrays by performing electrical transport measurements on Nb island arrays on Au at milli-kelvin temperatures and finite …
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Direct writing of three-dimensional nanostructures and their application in nanomagnetism
… the effect of 3D geometry on the magnetic domain walls and their dynamics have been studied. The purely geometry-driven domain wall motion in the fabricated 3D domain wall conduits has been experimentally demonstrated, offering a route towards fast, robust and energy efficient route for …
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Investigating Ferroelastic and Piezoelectric Vibration Damping Behavior in Nickel-Barium Titanate and Nickel-PZT Composites
… is due to the anelastic response of ferroelastic domain walls to applied external stress. In piezoelectric ceramics, vibration energy can also be dissipated through the direct piezoelectric effect if the appropriate electric circuit is connected across the ceramic. In this work we have examined …
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Computer Modeling and Simulation of Morphotropic Phase Boundary Ferroelectrics
… is investigated. It reveals characteristic multidomain microstructures, where nanoscale lamellar domains of tetragonal and rhombohedral phases coexist with well-defined crystallographic orientation relationships and produce coherent diffraction effects. (II) A bridging domain mechanism for …
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Design of materials with small magnetic hysteresis: the unexpected role of magnetostriction.
… based on linear stability analysis of the single domainstate on the shoulder of the hysteresis loop show that this method fails to predict the width of the hysteresis loop, a conclusion referred to as the ’coercivity paradox.’ We argue that the basic idea of using micromagnetics to predict …
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Domain wall dynamics and neuronic crackling noise
… likely to be present in each of the different domain walls that develop in four ferroelastic phases. Tetragonal and orthorhombic shear strains have values of 4-6% and 2-3% respectively, and are dominated by coupling with the order parameter for antiferroelectric-type displacements. Conversely, …
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Spectroscopic perspectives on ultrafast coupling phenomena in perovskite oxides
… of the high frequency phonons to ferroelastic domain walls in the material. I propose a new mechanism for the coupling of strain waves to the domain walls that is only effective for high amplitude strain. A detailed study of the phonon attenuation across a wide temperature range shows that the …
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Synthesis-Structure-Property Relationships in Lead-Free Piezoelectric Materials
… through microstructure optimization, domain engineering and multilayering. All these approaches are challenging and require innovation to make a significant impact on the current state-of-the-art. In this thesis, the later line of research was focused which is promising for near future …