Article
Physics, Applied
Hirofumi Ekawa, Jiaqi Shen, Kentaro Toyoki, Ryoichi Nakatani, Yu Shiratsuchi
Summary: We investigate the magnetoelectric switching of perpendicular exchange bias with low coercivity by optimizing the thickness of the Ir spacer layer in a Pt/Co/Ir/Cr2O3/Pt epitaxial film. The main impact of the Ir spacer layer is the significant reduction of coercivity, while maintaining both the perpendicular magnetic anisotropy and the perpendicular exchange bias.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jie Qi, Yunchi Zhao, Haochang Lyu, Guang Yang, He Huang, Jingyan Zhang, Jianxin Shen, Weidu Qin, Chaoqun Hu, Yang Gao, Yaqin Guo, Bokai Shao, Yi Zhang, Zhaozhao Zhu, Hongxiang Wei, Baogen Shen, Shouguo Wang
Summary: By introducing a 2-monolayer Cr insertion between layers, a twinning structure of the 7-ML ferromagnetic Co layer can be achieved, leading to a significant enhancement of Hall resistivity. Analysis of the crystalline structures suggests that the dominant contribution to Hall resistivity comes from skew scattering, with the remarkable enhancement of p(xy) attributed to the specific twinning structure.
Article
Materials Science, Multidisciplinary
Z. Kurant, S. K. Jena, R. Gieniusz, U. Guzowska, M. Kisielewski, P. Mazalski, I Sveklo, A. Pietruczik, A. Lynnyk, A. Wawro, A. Maziewski
Summary: We studied the magnetic properties of epitaxial Pt/W(d(w))/Co(d(Co))/Pt layered films as a function of W(d(w)) and Co(d(Co)) layer thicknesses. The influence of the bottom W layer on magnetic anisotropy, spin reorientation transition, and magnetic polarization of the interface atoms was observed. Different magnetic states were observed with decreasing Co layer thickness. The transition from hard to soft magnetic material with out-of-plane magnetization was found with changing W layer thickness. The domain structures at the out-of-plane state were sensitive to both Co and W layer thicknesses as well as the external magnetic field. Dzyaloshinskii-Moriya interaction was inferred from the Brillouin light scattering measurements.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
G. De Luca, J. Spring, U. Bashir, M. Campanini, R. Totani, C. Dominguez, A. Zakharova, M. Dobeli, T. Greber, M. D. Rossell, C. Piamonteze, M. Gibert
Summary: The study shows that LNMO thin films maintain insulating behavior and a stable Curie temperature, regardless of the epitaxial strain conditions. This suggests that this material could be used in multi-layer device architectures that require a high-temperature ferromagnetic insulating state.
Article
Multidisciplinary Sciences
Young Chan Won, Sang Ho Lim
Summary: The magnetic and interface properties of [Pt/Co/Pt] were studied, revealing different magnetic properties of the Co layer parts and the influence of the top Pt layer on the magnetic properties of the Co layer. Magnetometry was demonstrated as an effective tool for understanding the interface quality of magnetic multilayer systems.
SCIENTIFIC REPORTS
(2021)
Article
Nanoscience & Nanotechnology
Chloe S. Taylor, Marzieh Savadkoohi, Pawan Tyagi, Jenae E. Shoup, Dario A. Arena, Julie A. Borchers, James Eckert, Daniel B. Gopman
Summary: This study examines the role of sputter damage in limiting the perpendicular magnetic anisotropy and interlayer exchange coupling in Pt/Co/Ir-based synthetic antiferromagnets. By changing the process gas, the energy of backscattered sputter gas ions can be reduced, leading to an enhancement in the perpendicular magnetic anisotropy and interlayer exchange coupling energy.
ACS APPLIED NANO MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Krzysztof Szulc, Simon Mendisch, Michal Mruczkiewicz, Francesca Casoli, Markus Becherer, Gianluca Gubbiotti
Summary: The study delves into the spin-wave dynamics in single and double ferromagnetic layer systems, revealing the crucial role of layer deposition order on magnetic parameters, with significant differences in the magnetic anisotropy constant leading to distinct dispersion relations for spin-wave modes.
Article
Materials Science, Multidisciplinary
Lu Lu, Kun Liu, Shao-Bo Mi
Summary: The interfacial properties of the spinel/perovskite heterostructure at the Li0.5Fe2.5O4/(La, Sr)MnO3 interface have been investigated using transmission and scanning transmission electron microscopy techniques. Atomic-scale interface structures of Fe/(La,Sr)O, Fe/MnO2, and (Li,Fe)2O4/MnO2 have been determined for the Li0.5Fe2.5O4 and (La,Sr)MnO3 films with a cube-on-cube orientation relationship. Stacking faults in the Li0.5Fe2.5O4 film, along with interfacial dislocations, contribute to the epitaxial strain relaxation in the heterosystems. These findings contribute to a better understanding of the interfacial structure and physical properties in spinel/perovskite heterostructures.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Xiao-Ying Zhang, Duan-Chen Peng, Jing Han, Fang-Bin Ren, Shi-Cong Jiang, Ming-Chun Tseng, Yu-Jiao Ruan, Juan Zuo, Wan-Yu Wu, Dong-Sing Wuu, Chien-Jung Huang, Shui-Yang Lien, Wen-Zhang Zhu
Summary: Aluminum nitride (AlN) thin films with considerable properties were prepared using remote plasma atomic layer deposition (RP-ALD). The properties of AlN films with different growth temperatures were studied, and the characteristics of AlN/GaN and AlN/Al2O3 interfaces were analyzed on sapphire substrates. The experimental results showed that crystal AlN films with a hexagonal wurtzite structure were obtained at 250 degrees C. X-ray photoelectron spectroscopy confirmed the presence of Al-O, Al-O-N complexes, and Al-Al metallic aluminum bonds in the AlN films. High-resolution transmission electron microscopy revealed sharp interfaces of AlN/Al2O3 and AlN/GaN. Photoluminescence measurements confirmed that the AlN buffer layer enhances the quality of GaN grown on sapphire substrates. The high-quality AlN/GaN layers prepared by RP-ALD provide a promising pathway for high-quality GaN-based devices.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Movaffaq Kateb, Jon Tomas Gudmundsson, Snorri Ingvarsson
Summary: We optimized [(15 angstrom) Ni80Fe20/(5 angstrom) M]20 single crystal multilayers on (001) MgO substrates, and found that cube on cube epitaxial relationship can be achieved at a substrate temperature of 100 degrees C. Poly-crystalline multilayers were obtained at lower substrate temperatures, while {111} planes appeared at higher substrate temperatures. We also observed that higher epitaxial strain led to a rotation of the easy magnetization axis and increased coercivity values.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Bojun Zhao, Xiaojie Hu, Fuxiao Dong, Yan Wang, Haiou Wang, Weishi Tan, Dexuan Huo
Summary: This paper studied the magnetic behaviors and magnetocaloric effect of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate using pulsed laser deposition. The film showed a single orientation of (001) as observed by high-resolution X-ray diffraction. The temperature dependence of magnetization and magnetic field dependence of magnetization indicated a transition from paramagnetic to ferromagnetic state around the Curie temperature of approximately 193 K. The PSMO-7 film exhibited ferromagnetic properties at low temperatures and paramagnetic properties at higher temperatures. The maximum magnetic entropy change near the Curie temperature was found to be 4.7 J/kg K, indicating potential applications in magnetic refrigeration.
Article
Materials Science, Multidisciplinary
Joonghoe Dho
Summary: The study demonstrated significant differences in magnetic domain structure and perpendicular magnetic anisotropy on the flat and step-terrace surfaces of Pt/Co/Pt thin films.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Coatings & Films
Masashi Watanabe, Takafumi Kanauchi, Yoshihiro Chida, Kenta Hayashi, Naoto Todoroki, Toshimasa Wadayama
Summary: In this study, platinum nanostructures were prepared on epitaxial graphene layers, and their oxygen reduction reaction (ORR) properties were investigated. It was found that hydrogen-ion irradiation improved the electrochemical structural stability and ORR durability of the Pt nanostructures.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Chemistry, Physical
A. M. Engwall, L. B. Bayu Aji, A. A. Baker, S. J. Shin, J. H. Bae, S. K. McCall, J. D. Moody, S. O. Kucheyev
Summary: The study investigated the effects of substrate tilt on properties of gold-tantalum alloy films deposited by magnetron sputtering. It was found that the deposition rate and film density decrease with increasing substrate tilt angle, leading to changes in film properties such as porosity and electrical resistivity. The critical tilt angle for increased resistivity was determined to be between 40 and 60 degrees.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Takian Fakhrul, Siying Huang, Yixuan Song, Bharat Khurana, Geoffrey S. D. Beach, Caroline A. Ross
Summary: By measuring the motion of DWs as a function of current and in-plane magnetic field, it is shown that iDMI and DW width do not scale linearly with lattice mismatch strain, but are dependent on the substrate. The largest iDMI obtained was 0.007 mJ m-2, from three substrates of different compositions. Total anisotropy, however, does increase linearly with lattice parameter, indicating a dominant magnetoelastic anisotropy contribution. The sensitivity of iDMI and anisotropy to substrate composition provides opportunities for engineering homochiral magnetic structures and their dynamics.
Article
Chemistry, Physical
Thomas Cadenbach, Pamela Santillan, A. Lucia Morales, Maria J. Benitez, Fernando Moncada, Luis Lascano, Cesar Costa-Vera, Valeria Ochoa-Herrera, Karla Vizuete, Alexis Debut
Summary: Bi1-xMxFeO3 porous networks were synthesized using a glycine-nitrate combustion technique and applied in photocatalytic degradation reactions under visible light irradiation, with different rare-earth dopants showing enhanced optical properties and photocatalytic activities. The Bi0.95Gd0.05FeO3 sample demonstrated the highest overall photocatalytic activity and stability, surpassing previously reported doped nanoparticles, making it a promising candidate for industrial wastewater treatment applications.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Gary W. Paterson, Gavin M. Macauley, Stephen McVitie, Yoshihiko Togawa
Summary: In the first part of this work, we introduce the TEM-DPC technique for quantifying phase gradients of samples with structural contrast, compared to the TIE method. The TEM-DPC technique is particularly suitable for in situ studies and complements the TIE method due to its ability to handle structural contrast.
MICROSCOPY AND MICROANALYSIS
(2021)
Article
Materials Science, Ceramics
Thomas Cadenbach, Maria J. Benitez, Sofia Andrade Tirado, Valeria Ochoa-Herrera, Alexis Debut, Karla Vizuete
Summary: BiFeO3 nanomaterials have attracted much interest as effective visible-light photocatalysts for water splitting and organic pollutant degradation due to their narrow band gap energies. The use of GdxBi1-xFeO3@SBA-15 nanocomposites can achieve high removal efficiency of the organic dye Rhodamine B, with the 10 vol% Gd0.05Bi0.95FeO3@SBA-15 sample showing the best performance. The synergistic adsorption enhanced photocatalytic degradation process contributes to the superior efficiencies of the nanocomposites over their parent compounds.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Alison Cowan, Kevin McNeill, Muhammad Bilal Janjua, Stephen McVitie
Summary: The study investigated the impact of ultra-thin Ni79Fe21 seed layers on the physical and magnetic behavior of Ni45Fe55 films. The addition of seed layers reduced grain size, improved film texture, and enhanced magnetic properties. The use of magnetic microscopy allowed for precise characterization of the material's magnetic structure.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Claire Donnelly, Aurelio Hierro-Rodriguez, Claas Abert, Katharina Witte, Luka Skoric, Dedalo Sanz-Hernandez, Simone Finizio, Fanfan Meng, Stephen McVitie, Jorg Raabe, Dieter Suess, Russell Cowburn, Amalio Fernandez-Pacheco
Summary: The design of complex magnetic systems through nonlinear interactions or three-dimensional geometries can achieve new functionalities by controlling intrastructure properties and magnetostatic coupling of neighboring magnetic structures. This can lead to new physics and functionalities, such as three-dimensional chiral spin states and spin textures with new spin topologies.
NATURE NANOTECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Callum R. MacKinnon, Katharina Zeissler, Simone Finizio, Jorg Raabe, Christopher H. Marrows, Tim Mercer, Philip R. Bissell, Serban Lepadatu
Summary: In this study, the effect of an additional interfacial spin-transfer torque on skyrmion collections in ultrathin metal/ferrimagnetic multilayers was investigated. The results showed that the inclusion of interfacial spin-transfer torque reduced the skyrmion Hall angles, which was consistent with experimental observations. The velocity of the skyrmion collections was found to be independent of the diameter, unlike isolated skyrmions. The calculated skyrmion velocities were also comparable to experimental results when the interfacial spin-transfer torque was considered.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
A. Magni, G. Carlotti, A. Casiraghi, E. Darwin, G. Durin, L. Herrera Diez, B. J. Hickey, A. Huxtable, C. Y. Hwang, G. Jakob, C. Kim, M. Klaui, J. Langer, C. H. Marrows, H. T. Nembach, D. Ravelosona, G. A. Riley, J. M. Shaw, V. Sokalski, S. Tacchi, M. Kuepferling
Summary: Experimental studies using magneto-optics have shown a correlation between domain wall roughness and interface roughness of sample layers, with standard creep hypothesis models unable to accurately reproduce domain wall velocity profiles under high roughness conditions. Comparison with Brillouin light scattering measurements revealed that the latter method often yields higher measured values of Dzyaloshinskii-Moriya interaction.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Chemistry, Analytical
M. Cubukcu, S. Poellath, S. Tacchi, A. Stacey, E. Darwin, C. W. F. Freeman, C. Barton, B. J. Hickey, C. H. Marrows, G. Carlotti, C. H. Back, O. Kazakova
Summary: This study shows that magnetic skyrmions can be stabilized at room temperature in continuous [Ir/Co/Pt](5) multilayers on SiO2/Si substrates without the prior application of electric current or magnetic field. The transition of magnetic domain patterns from worm-like state to separated stripes is observed by decreasing the Co thickness. The density of skyrmions can be significantly enhanced after applying the in-plane field procedure, providing means to manipulate their density and optimize skyrmion-based devices.
Article
Biochemistry & Molecular Biology
David Giancarlo Garcia, Cristina Garzon-Romero, Mateo Alejandro Salazar, Karina J. Lagos, Kleber Orlando Campana, Alexis Debut, Karla Vizuete, Miryan Rosita Rivera, Dario Niebieskikwiat, Maria J. Benitez, Maria Paulina Romero
Summary: This study presents a quick and easy green synthesis method using waste orange peel extract as a reducing, capping, and stabilizing agent to prepare magnetic nanoparticles based on iron oxides (MNPs-Fe). The 50GS-MNPs-Fe sample showed an excellent mass yield and a particle size of about 50 nm with an organic coating.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Physics, Applied
Christopher E. A. Barker, Eloi Haltz, Thomas. A. Moore, Christopher H. Marrows
Summary: In this study, the breathing modes of skyrmions in a synthetic antiferromagnetic multilayer were investigated using micromagnetic simulations. The modes were found to split into different arrangements of out-of-phase, in-phase, and modes with more complex phase relationships, resulting in a lowering of frequencies. This has promising implications for skyrmion sensing applications in a synthetic antiferromagnet.
JOURNAL OF APPLIED PHYSICS
(2023)
Review
Physics, Multidisciplinary
M. Kuepferling, A. Casiraghi, G. Soares, G. Durin, F. Garcia-Sanchez, L. Chen, C. H. Back, C. H. Marrows, S. Tacchi, G. Carlotti
Summary: This review examines the state of the art measurement techniques for the Dzyaloshinskii-Moriya interaction constant (DMI constant D), particularly in systems where the DMI arises from the interface between two materials. The review provides an overview of experimental techniques, theoretical background, and models for quantifying the DMI constant. The measurement techniques are categorized into three types: domain-wall-based measurements, spin-wave-based measurements, and spin-orbit torque-based measurements. The advantages and disadvantages of each method are analyzed, and the D values at different interfaces are compared. The review aims to improve understanding of the applicability of different techniques and explain discrepancies in literature values.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Kevin J. A. Franke, Colin Ophus, Andreas K. Schmid, Christopher H. Marrows
Summary: We used spin-polarized low-energy electron microscopy to study domain pattern transfer in a multiferroic heterostructure consisting of a (111)-oriented BaTiO3 substrate and an epitaxial Ni film. Interfacial strain transfer and inverse magnetostriction induce a uniaxial in-plane magnetic anisotropy that rotates between alternating stripe regions. Two types of magnetic domain walls can be initialized, and the competition between exchange and magnetostatic energies influences the magnetic domain configuration.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Applied
Christopher Barker, Simone Finizio, Eloi Haltz, Sina Mayr, Philippa M. Shepley, Thomas A. Moore, Gavin Burnell, Joerg Raabe, Christopher H. Marrows
Summary: The use of high current densities in magnetic racetrack memories results in significant wire heating and wasted energy. Synthetic antiferromagnets have shown fast domain wall (DW) motion at high current densities, but the behavior at lower current densities has received less attention. By using scanning transmission x-ray microscopy, this study found that DWs depin at (3.5 +/- 0.4) x10(11) A m(-2) and show faster motion in response to 5 ns duration current pulses compared to multilayers without antiferromagnetic coupling. These results suggest that DWs in synthetic antiferromagnets are superior for low energy consumption racetrack technologies.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Lin Huang, Gavin Burnell, Christopher H. Marrows
Summary: In this study, the motion of a skyrmion driven by propagating spin waves in a thin film track with interfacial perpendicular magnetic anisotropy and Dzyaloshinskii-Moriya interaction was investigated using numerical micromagnetic simulations. It was found that the skyrmion always moves in the direction of the spin-wave propagation at long simulation times. However, at shorter times, the skyrmion shows transient retrograde motion when the track width is wider than 50 nm or for certain values of Gilbert damping. The observed motion can be explained by considering the gyrotropic and dissipative effects as well as the repulsive force from the edges of the track.
Article
Materials Science, Multidisciplinary
K. M. Seemann, O. Gomonay, Y. Mokrousov, A. Horner, S. Valencia, P. Klamser, F. Kronast, A. Erb, A. T. Hindmarch, A. Wixforth, C. H. Marrows, P. Fischer
Summary: In this study, it is shown that surface acoustic waves can be used to identify complex magnetic phases that arise during the evolution of exchange springs in an applied field at prototype ferromagnet-antiferromagnet interfaces. The findings provide a complementary and integrative insight into emergent magnetic materials for the applications of noncollinear spin textures in low-energy-consumption spintronic devices.
