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Results for “MAGNETOSTRICTION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Magnetostriction of α-RuCl 3 Flakes in the Zigzag Phase

Motivated by the possibility of enhanced magnetic fluctuations in exfoliated α-RuCl 3 flakes, we study magneto-Raman spectra of exfoliated multilayer α-RuCl 3 in out-of-plane magnetic fields of -6 to 6 T at temperatures of 670 mK to 4 K. While the literature currently suggests that bulk α-RuCl 3 is in an antiferromagnetic zigzag phase with R$\bar3$ symmetry at low temperatures, we do not observe R$\bar3$ symmetry in exfoliated α-RuCl 3 at low temperatures. While we saw no magnetic field-driven transitions, the Raman modes exhibit unexpected stochastic shifts in response to the applied magnetic field that are above the uncertainties inferred from Bayesian analysis. Finally, these stochastic shifts are consistent with the emergence of magnetostrictive interactions in exfoliated α-RuCl 3 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Imaging of voltage-controlled switching of magnetization in highly magnetostrictive epitaxial Fe–Ga microstructures

The magnetoelectric behavior of epitaxial Fe–Ga microstructures on top of a (001)-oriented PMN–PT piezoelectric substrate is imaged with magnetic X-ray microscopy. Additionally, the micron-scale strain distribution in PMN–PT is characterized by X-ray microdiffraction and examined with respect to the results of the Fe–Ga magnetoelectric switching. The magnetic reorientation of Fe–Ga is found to be strongly correlated with size, shape, and crystallographic orientation of the microstructures. In the case of square-shaped structures, size dictates the influence of the strain distribution on both the initialization of the ground state and on the magnetic reorientation during application of voltage. On the other hand, elliptical microstructures demonstrate completely different magnetic responses depending on the relative orientation of their long axis with respect to the crystallographic directions of the PMN–PT. This study demonstrates that engineering the behavior of highly magnetostrictive epitaxial microdevices is possible. It further elucidates that voltage-induced actuation can be largely tuned to achieve the desired type of magnetic switching ranging from vortex circulation reversal, domain wall motion, to a large rotation of magnetization. Because of the outstanding properties of the investigated material system, the reported findings are expected to be of great interest for the realization of next-generation energy-efficient magnetic memory and logic devices.

42 ENGINEERING↗
DOE OSTI2016

Strong anisotropy and magnetostriction in the two-dimensional Stoner ferromagnet Fe 3 GeTe 2

Computationally characterizing magnetic properies of novel two-dimensional (2D) materials serves as an important first step of exploring possible applications. Using density-functional theory, we show that single-layer Fe 3 GeTe 2 is a potential 2D material with sufficiently low formation energy to be synthesized by mechanical exfoliation from the bulk phase with a van der Waals layered structure. In addition, we calculated the phonon dispersion demonstrating that single-layer Fe 3 GeTe 2 is dynamically stable. Furthermore, we find that similar to the bulk phase, 2D Fe 3 GeTe 2 exhibits amagnetic moment that originates from a Stoner instability. In contrast to other 2D materials, we find that single-layer Fe 3 GeTe 2 exhibits a significant uniaxial magnetocrystalline anisotropy energy of 920μ eV per Fe atom originating from spin-orbit coupling. In conclusion, we show that applying biaxial tensile strains enhances the anisotropy energy, which reveals strong magnetostriction in single-layer Fe 3 GeTe 2 with a sizable magneostrictive coefficient. Our results indicate that single-layer Fe 3 GeTe 2 is potentially useful for magnetic storage applications.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Compositional Design of Soft Magnetic High Entropy Alloys by Minimizing Magnetostriction Coefficient in (Fe 0.3 Co 0.5 Ni 0.2 ) 100-x (Al 1/3 Si 2/3 ) x System

Developing cost-effective soft magnetic alloys with excellent mechanical properties is very important to energy-saving industries. This study investigated the magnetic and mechanical properties of a series of (Fe 0.3 Co 0.5 Ni 0.2 ) 100–x (Al 1/3 Si 2/3 ) x high-entropy alloys (HEAs) (x = 0, 5, 10, 15, and 25) at room temperature. The Fe 0.3 Co 0.5 Ni 0.2 base alloy composition was chosen since it has very the smallest saturation magnetostriction coefficient. It was found that the (Fe 0.3 Co 0.5 Ni 0.2 ) 95 (Al 1/3 Si 2/3 ) 5 alloy maintains a simple face-centered cubic (FCC) solid solution structure in the states of as-cast, cold-rolled, and after annealing at 1000 °C. The alloy after annealing exhibits a tensile yield strength of 235 MPa, ultimate tensile strength of 572 MPa, an elongation of 38%, a saturation magnetization (Ms) of 1.49 T, and a coercivity of 96 A/m. The alloy not only demonstrates an optimal combination of soft magnetic and mechanical properties, it also shows advantages of easy fabrication and processing and high thermal stability over silicon steel and amorphous soft magnetic materials. Therefore, the alloy of (Fe 0.3 Co 0.5 Ni 0.2 ) 95 (Al 1/3 Si 2/3 ) 5 holds good potential as next-generation soft magnets for wide-range industrial applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Electrodeposition processes for magnetostrictive resonators

The present invention relates to magnetoelastic resonators, sensors, and tunable devices, as well as methods for making such components. The resonators can be used as tags and/or sensors. In general, the resonators include one or more micron-sized resonator portions affixed on a substrate. For use as a tag, each tag includes a plurality of resonator portions that allow for multiplexed coding, and methods for making tags and arrays of such tags include use of electrodeposition processes. In particular embodiments, these components include an electrodeposited material that exhibits magnetostrictive properties.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Electrodeposition processes for magnetostrictive resonators

The present invention relates to magnetoelastic resonators, sensors, and tunable devices, as well as methods for making such components. The resonators can be used as tags and/or sensors. In general, the resonators include one or more micron-sized resonator portions affixed on a substrate. For use as a tag, each tag includes a plurality of resonator portions that allow for multiplexed coding, and methods for making tags and arrays of such tags include use of electrodeposition processes. In particular embodiments, these components include an electrodeposited material that exhibits magnetostrictive properties.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Rare-earth orbital moment contributions to the magnetic anisotropy in magnetostrictive Tb0.3Dy0.7Fe2

Soft x-ray Magnetic Circular Dichroism spectroscopy at the Dy and Tb M4,5 and the Fe L2,3 edges was performed on a sputter deposited polycrystalline Terfenol-D (Tb0.3Dy0.7Fe2) film on sapphire substrates at temperatures from 100 to 300 K to evaluate the elementwise contribution to the magnetocrystalline anisotropy and coercive field. The elemental spin and orbital magnetic moments were calculated using the x-ray Magnetic Circular Dichroism sum rules. As temperatures decreased, the Tb and Fe moments plateau at 200 K with values of 7.6 μB/atom and 1.8 μB/atom, respectively, while the Dy moment increases to 8.9 μB/atom at 100 K. Between 300 and 200 K, the change in magnetic anisotropy is dominated by thermally induced magnetoelastic effects while for temperatures below 200 K magnetocrystalline anisotropy (MCA) changes are dominant. The MCA changes below 200 K appear to be due to increases in the Dy orbital moment with decreasing temperature in this temperature regime.

Shirazi, Paymon (ORCID:0000000256954597)↗