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Showing 1 to 12 of 12 for “"chemical ordering"”.
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Studies of Structural and Chemical Ordering in Metallic Liquids and Glasses Using Electrostatic Levitation
… liquids and glasses reveal signatures of chemical ordering in the liquid with decreasing temperature and evidence for accelerated ordering in the deeply supercooled state. Novel experimental measurements and Reverse Monte Carlo simulations of the structure of bulk glass-forming …
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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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Systematic analysis of the crystal structure, chemical ordering, and microstructure of Ni-Mn-Ga ferromagnetic shape memory alloys
Ni-n-Ga based ferromagnetic shape-memory alloys (FSMAs) have shown great promise as an active material that yields a large output strain over a range of actuation frequencies. The maximum strain has been reported to be 6% in the tetragonal martensitic phase and up to 10% in the orthorhombic phase. …
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Magnetic Weyl Semimetals for Spintronic Applications
… develop a series of MTJs with varying degrees of chemical ordering in the Weyl semimetal electrodes and compare their tunneling magnetoresistance (TMR). I find that the TMR is enhanced with the improvement of the chemical ordering in Co₂MnGa. Our results reveal the relationship between the spin …
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Nanocrystalline Fe-Pt alloys: phase transformations, structure and magnetism
… to the study of phase transformations involving chemical ordering and magnetic properties evolution in bulk Fe-Pt alloys composed of nanometer-sized grains. A comprehensive study of phase transformations and ordering in Fe-Pt alloys is performed by a combination of in-situ neutron powder …
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Magnetism and interactions within the single domain limit: reversal, logic and information storage
… temperature post annealing would facilitate L10 chemical ordering. For FePt thin film samples, reversal process and magnetic behavior were studied for both continuous film and patterned dots array. Further, patterned dots arrays within different length scale were developed to reveal the …
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Structural characterization of multimetallic nanoparticles
… lattice contraction and <em>L</em>1<sub>0</sub>chemical ordering. The mass transport involved in sintering is attributed to grain boundary diffusion and its corresponding activation energy is estimated from the data analysis. ^ Nanoscale alloying and phase transformations in physical mixtures of …
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A combined experimental and computational study of nanopaleomagnetic recorders in meteoritic metal
… DFT was also used to explore the preferred chemical ordering schemes of the matrix as well as its ground magnetic state. The 3D structure of the cloudy zone was imaged with sub-nanometer resolution using Atom Probe Tomography (APT). This was one of the first applications of APT to image …
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Spin cluster expansion approach to the interplay between short-range order and interstitial atoms in austenitic stainless steels
… including the derivation of SRO parameters and chemical pairwise interactions from the CE model. While the CE model successfully captures the ground states of the Fe–Ni–Cr–H system, its predictions on SRO show noticeable deviations from experimental measurements. These discrepancies highlight …
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Machine-Learning Assisted Atomic Simulations of Defect Dynamics in Multicomponent Concentrated Alloys
… the intricacies of local atomic arrangements and chemical heterogeneities influence diffusion processes, thereby offering new insights into alloy design and optimization. The research initially focuses on the vacancy-mediated diffusion employing binary Ni-Fe concentrated alloys as model systems. …
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Wachstum und Realstruktur von epitaktischen (Al,Ga)N-Schichten
In der vorliegenden Arbeit wird der Einfluss der Wachstumsparameter auf die Realstruktur von binären GaN-, AlN- und ternären (Al,Ga)N-Schichten untersucht. Die Abscheidung der Schichten erfolgte heteroepitaktisch mittels Molekularstrahlepitaxie (MBE) auf den Substraten Al2O3 (0001), Si (111) und …
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Atomistic modelling of precipitation in Ni-base superalloys
… to investigate the onset of $\gamma^{\prime}$ ordering in Ni-Al single crystals and in Ni-Al bicrystals containing coincidence site lattice grain boundaries (GBs) and we do this at high temperatures, which are representative of typical heat treatment schedules including quenching and annealing. …