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Showing 1 to 20 of 20 for “"FePt"”.
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Filmes de FePt para dispositivos da spintrônica
… magnetic and transport properties in the L10 FePt compound. The compound has tetragonal structure and strong magnetocrystalline anisotropy. Films were prepared by sputtering. For measuring Tunnel Anisotropic Magnetoresistance (TAMR), FePt/AlOx/Au trilayers were prepared. All prepared alloys …
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Growth, structure and magnetic properties of magnetron sputtered FePt thin films
The L10 FePt phase belongs to the most promising hard ferromagnetic materials for high density recording media. The main challenges for thin FePt films are: (i) to lower the process temperature for the transition from the soft magnetic A1 to the hard magnetic L10 phase, (ii) to realize c-axes …
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Effects of AG on structural and magnetic properties of FePt thin films
… performance, Ag was added into perpendicular FePt thin films by cosputtering and sequential sputtering. Cosputtered with Ag, FePt grain size and magnetic exchange coupling were reduced with increasing Ag content. A study on alloying of FePt-Ag indicated that most Ag atoms formed a separate …
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Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands
… dissertation, we explored the fabrication of FePt nanoparticles and nano-islands with the face-centered tetragonal (fct, L10) phase prepared by both chemical synthesis routes and physical vapor deposition. Microstructure and magnetic properties characterizations were used to gain a fundamental …
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Synthesis and characterization of silicon nanowires, silicon nanorods, and magnetic nanocrystals
… single domain, antiferromagnetic L1₂ FePt₃ and ferromagnetic L1₀ FePt nanocrystals were synthesized by coating colloidally-grown Pt-rich or stoichiometricly equal Fe-Pt nanocrystals with thermally-stable SiO₂ and annealing at high temperature. Without the silica coating, the …
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Manipulation and Characterization of Morphology and Composition in Mono- and Heterometallic Nanoparticles
… or plasmonics. The synthetic development of FePt@Fe3O4 by the thermal decomposition of Fe(CO)5 upon a preformed FePt seed with enhanced Fe3O4 shell thickness control whilst avoiding the primary-nucleation of Fe3O4 impurities was achieved. The coating of non-magnetic Pt cores established that …
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Polystyrene coated iron-platinum drug delivery platforms for theranostics
… developments in cancer research.4 Iron-platinum (FePt) nanoparticles have an excellent potential as delivery agents for medicinal applications. Superparamagnetic FePt nanoparticles were embedded in a surface-functionalized polymeric shell as drug delivery platforms. The FePt core offers improved …
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Magnetism and interactions within the single domain limit: reversal, logic and information storage
… studied. High quality epitaxial L10 FePdPt and FePt thin films on MgO (001) substrate was fabricated. For FePd binary alloy thin films, we observed that Pt addition and low temperature post annealing would facilitate L10 chemical ordering. For FePt thin film samples, reversal process and …
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The role of copper on stress evolution and chemical ordering in iron-copper-platinum thin films
The chemical ordering of FePt requires an annealing temperature >500 °C. At these temperatures, grain growth attributed to thermal annealing lowers the areal density in computer hard drives. Multiple paths have been proposed to lower the ordering temperature in order to decrease the grain growth. …
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Synthesis, structure and magnetic properties of nanowires and films by electrodeposition
… nanowires. In addition, NiCo, NiCu, CoCu, and FePt wires have also been successfully fabricated. The layer and bamboo structure in NiCo gives the possibility to control the microstructures of nanowires. Moreover, relatively thick FePt films by electrodeposition have been investigated. By doping …
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Magnetisch und katalytisch funktionalisierte mesoporöse Materialien
… Eigenschaften erhalten. Dagegen resultierte für FePt-Systeme nach der Reduktion bei 750 °C bis 800 °C eine deutliche Zunahme der Raumtemperaturkoerzitivitäten auf bis zu 28,35 kOe (FePt@CMK-3) bzw. 15,60 kOe (FePt@SBA-15) infolge der Bildung der intermetallischen fct-FePt Verbindung. Weiterhin …
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Density-Functional Theory+Dynamical Mean-Field Theory Study of the Magnetic Properties of Transition-Metal Nanostructures
… properties of small (2 to 5-atom) Fe and FePt clusters provide meaningful results: dynamical effects lead to a reduction of the cluster magnetic moment as compared to that obtained from DFT or DFT+U (U being the Coulomb repulsion parameter). We have subsequently developed our own …
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High Anisotropy Magnetic Materials for Data Storage and Spintronic Memory
… to advance understanding of: development of FePt for HAMR media, effect of strain assisted switching on the spin state of FePt, and development of novel high anisotropy Mn-based materials with low magnetization. Finally, I will present my experimental realization of Ru as the 4th room …
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Micromagnetic Study of Composite Media for High Density Heat Assisted Magnetic Recording
… Landau-Lifshitz-Gilbert (LLG) method. L10 FePt is one promising recording media candidate for HAMR. The transition noise and transition jitter are calculated through magnetic recording simulation accelerated by GPU parallel computing. Thermal fluctuations and Curie temperature variance are …
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Synthesis, characterization and modification of carbon nanomaterials
… terminated CNT, i.e. CNT with a FePt nanoparticle at each tip, are directly grown using FePt catalysts. Fe/Pt thin films with a strongly over-stoichiometric Fe content in the starting catalyst composition yield CNT with a significant number of particles in the hard-magnetic phase. …
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Nanocrystalline Fe-Pt alloys: phase transformations, structure and magnetism
… the formation of chemically highly ordered L10 FePt and, in the case of the Fe-rich and Pt-rich compositions, L12 Fe3Pt and FePt3 phases, respectively. Whereas in Pt-rich alloys the decoupling effect of the FePt3 phase leads to coercivity improvement, in Fe-rich nanocomposites a peculiar …
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The Influence Of Gender And Aging On The Neural Circuitry Supporing Facial Emotion Processing In Adults With Major Depressive Disorder
… completed a facial emotion processing task (FEPT) while undergoing functional magnetic resonance imaging (fMRI). Interactions were revealed between MDD status, gender, and age group in a number of brain regions important to emotion processing. These regions included the inferior, middle, and …
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Block copolymer self-assembly : lithography, magnetic fabrication, and optimization
… including magnetic materials like cobalt, Co/Pd, FePt and CoFeB magnetic tunnel junctions (MTJ), and MoS2 monolayers. For magnetic nanowire arrays, the interactions between neighboring wires are investigated. For perpendicular MTJ nanopillar arrays, the size-dependent switching behavior and …
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Quantitative High-angle Annular Dark Field Scanning Transmission To Electron Microscopy For Materials Science
… to assess the degree of chemical order in small FePt L10 nanoparticles by implementing a CBED diffraction technique. Unexpectedly, the degree of order of individual particles is highly variable and not a simple function of particle size or sample composition. The particle-to-particle variability …
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Low temperature Kerr effect study of magnetic topological insulators and other magnetic structures
… for spin transport experiments, including $L1_0$-FePt/MgO/GaAs and [Co/Pt]$_n$/GaAs. None of them show promising magnetisation features for the further pursuit of spin injection into semiconductors. Finally, the surface science of a few magnetic and non-magnetic materials is investigated using low …