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11 pages, 5820 KiB

Open AccessArticle

Enhancing the Thermal Stability of Skyrmion in Magnetic Nanowires for Nanoscale Data Storage

by Mohammed Al Bahri, Mohammed Al Hinaai, Rayya Al Balushi and Salim Al-Kamiyani

Nanomaterials 2024, 14(21), 1763; https://doi.org/10.3390/nano14211763 - 3 Nov 2024

Cited by 2 | Viewed by 1486

Magnetic skyrmion random switching and structural stability are critical limitations for storage data applications. Enhancing skyrmions’ magnetic properties could improve their thermal structural stability. Hence, micromagnetic calculation was carried out to explore the thermal nucleation and stability of skyrmions in magnetic nanodevices. Different magnetic properties such as uniaxial magnetic anisotropy energy (Ku), saturation magnetization (Ms) and Dzyaloshinskii—Moriya interaction (DMI) were used to assess the thermal stability of skyrmions in magnetic nanowires. For some values of Ms and Ku, the results verified that the skyrmion structure is stable at temperatures above 800 K, which is higher than room temperature. Additionally, manipulating the nanowire geometry was found to have a substantial effect on the thermal structural stability of the skyrmion in storage nanodevices. Increasing the nanowire dimensions, such as length or width, enhanced skyrmions’ structural stability against temperature fluctuations in nanodevices. Furthermore, the random nucleation of the skyrmions due to the device temperature was examined. It was shown that random skyrmion nucleation occurs at temperature values greater than 700 K. These findings make skyrmion devices suitable for storage applications. Full article

(This article belongs to the Special Issue Magnetism and Spintronics at the Nanoscale)

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10 pages, 2151 KiB

Open AccessArticle

Measurement of the Dzyaloshinskii–Moriya Interaction in Mn₄N Films That Host Skyrmions

by Wei Zhou, Chung Ting Ma and S. Joseph Poon

Nanomaterials 2023, 13(10), 1672; https://doi.org/10.3390/nano13101672 - 18 May 2023

Cited by 2 | Viewed by 2975

Abstract

Mn₄N thin film is one of the potential magnetic mediums for spintronic devices due to its ferrimagnetism with low magnetization, large perpendicular magnetic anisotropy (PMA), thermal stability, and large domain wall velocity. Recent experiments confirmed the existence of tunable magnetic skyrmions in MgO/Mn₄N/Cu_xPt_1−x(x = 0, 0.5, 0.9, 0.95), and density functional theory (DFT) calculation provided a large theoretical value of the interfacial Dzyaloshinskii–Moriya interaction (iDMI) of Mn₄N/Pt, which is consistent with the predicted chemical trend of the DMI in transition metal/Pt films. So far, the measured DMI has not been reported in Mn₄N, which is needed in order to support the predicted large DMI value. This paper reports the average DMI of MgO/Mn₄N(17 nm)/Cu_xPt_1−x(3 nm) extracted from the anomalous Hall effect with various tilted angles, which is based on magnetic droplet theory with DMI effects. The DMI decreases from 0.267 mJ/m² to 0.011 mJ/m² with non-linear tendencies as Cu concentration in the Cu_xPt_1−x capping layer increases from 0 to 1, demonstrating the control of the DMI through the Cu_xPt_1−x capping layer. Furthermore, a solid solution model is developed based on an X-ray photoelectron spectroscopy (XPS) compositional depth profile to analyze the possible effects on the DMI from the mixing layers at the surface of Mn₄N. After taking into account the mixing layers, the large DMI in Mn₄N film with Pt capping is consistent with the predicted DMI. Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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11 pages, 4618 KiB

Open AccessArticle

Characterization of a Disordered above Room Temperature Skyrmion Material Co₈Zn₈Mn₄

by Melissa E. Henderson, James Beare, Sudarshan Sharma, Markus Bleuel, Pat Clancy, David G. Cory, Michael G. Huber, Casey A. Marjerrison, Mathew Pula, Dusan Sarenac, Evan M. Smith, Kirill Zhernenkov, Graeme M. Luke and Dmitry A. Pushin

Materials 2021, 14(16), 4689; https://doi.org/10.3390/ma14164689 - 19 Aug 2021

Cited by 15 | Viewed by 3273

Abstract

Topologically nontrivial spin textures host great promise for future spintronic applications. Skyrmions in particular are of burgeoning interest owing to their nanometric size, topological protection, and high mobility via ultra-low current densities. It has been previously reported through magnetic susceptibility, microscopy, and scattering [...] Read more.

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forms an above room temperature triangular skyrmion lattice. Here, we report the synthesis procedure and characterization of a polycrystalline Co

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disordered bulk sample. We employ powder X-ray diffraction and backscatter Laue diffraction as characterization tools of the crystallinity of the samples, while magnetic susceptibility and Small Angle Neutron Scattering (SANS) measurements are performed to study the skyrmion phase. Magnetic susceptibility measurements show a dip anomaly in the magnetization curves, which persists over a range of approximately 305 K–315 K. SANS measurements reveal a rotationally disordered polydomain skyrmion lattice. Applying a symmetry-breaking magnetic field sequence, we were able to orient and order the previously jammed state to yield the prototypical hexagonal diffraction patterns with secondary diffraction rings. This emergence of the skyrmion order serves as a unique demonstration of the fundamental interplay of structural disorder and anisotropy in stabilizing the thermal equilibrium phase. Full article

(This article belongs to the Section Quantum Materials)

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