Article
Chemistry, Physical
Hongchang Wang, Pengqiang Hu, Zhengming Zhang, Dunhui Wang
Summary: Magnetostructural coupling materials have excellent magnetocaloric properties and are ideal candidates for magnetic refrigerants. By adding Co into the Ge site of Tb5Si2Ge2, a strong magnetostructural coupling can be achieved, significantly improving the magnetocaloric properties of the compound. Experimental results show that the magnetic entropy change and temperature-averaged entropy change are increased after Co doping, indicating an enhanced low-field magnetocaloric performance. Theoretical calculations also confirm a large lattice entropy change after the magnetostructural transformation. These findings demonstrate that Co doping can transform Tb5Si2Ge2 into an excellent magnetic refrigerant.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
R. Martinho Vieira, O. Eriksson, A. Bergman, H. C. Herper
Summary: This study aims to predict new materials for magnetic refrigeration through high-throughput calculations, focusing on the lattice entropy in the FeRh system. It points out the limitations and applicability of commonly used approximation methods in this field.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Inorganic & Nuclear
K. Laajimi, F. Ayadi, M. Kchaw, I Fourati, M. Khlifi, M. H. Gazzah, J. Dhahri, J. Juraszek
Summary: The influence of strontium doping on the structural, magnetic, and magnetocaloric properties of La-based complex oxides has been investigated. Different crystal structures were observed for samples with varying doping concentrations. The magnetic entropy change measurements showed that strontium doping significantly affects the magnetic properties of the material, making it a potential candidate for magnetic refrigeration applications.
SOLID STATE SCIENCES
(2021)
Article
Computer Science, Interdisciplinary Applications
S. E. Rannala, A. Meo, S. Ruta, W. Pantasri, R. W. Chantrell, P. Chureemart, J. Chureemart
Summary: Micromagnetic modelling is a reliable method for simulating large magnetic systems and overcomes the computational limitations of atomistic modelling. By combining three key solvers, it enables accurate simulation of magnetization dynamics in complex systems at different timescales. This approach has significant applications in the research and development of magnetic recording media.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Philip A. E. Murgatroyd, Kieran Routledge, Samantha Durdy, Michael W. Gaultois, T. Wesley Surta, Matthew S. Dyer, John B. Claridge, Stanislav N. Savvin, Denis Pelloquin, Sylvie Hebert, Jonathan Alaria
Summary: Magneto-caloric materials have the potential for environmentally friendly thermal management devices, but developing solid-state technology faces challenges in material selection and performance control. The study of compounds derived from the PbFCl structure reveals that the c/a parameter can be used as an accurate proxy to control magnetic transition, and chemical substitution allows tuning of Curie temperature over a broad temperature span.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Pierre-Olivier Jubert, Tiffany Santos, Thanh Le, Burak Ozdol, Cristian Papusoi
Summary: The study explores the relevance of anisotropic heatsinks for HAMR, finding that their performance is determined by in-plane thermal conductivity. TDTR measurements extracted the thermal conductivities of a (Cu/Ta) multilayer heatsink, demonstrating its potential as a candidate for HAMR with high in-plane thermal conductivity.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Nanoscience & Nanotechnology
Wei Zhang, Tian Xun Huang, Michel Hehn, Gregory Malinowski, Maxime Verges, Julius Hohlfeld, Quentin Remy, Daniel Lacour, Xin Ran Wang, Guo Ping Zhao, Pierre Vallobra, Yong Xu, Stephane Mangin, Wei Sheng Zhao
Summary: Manipulating magnetic skyrmions using a femtosecond laser pulse has attracted attention due to their potential applications in energy-efficient information-storage devices. However, the mechanism for the creation of skyrmions induced by an fs laser is still unknown, and the challenge lies in understanding the transition from trivial to nontrivial magnetic states.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Zhang Wei, Huang Tian Xun, Michel Hehn, Gregory Malinowski, Maxime Verges, Julius Hohlfeld, Quentin Remy, Daniel Lacour, Wang Xin Ran, Zhao Guo Ping, Pierre Vallobra, Xu Yong, Stephane Mangin, Zhao Wei Sheng
Summary: This study demonstrates that the laser-magnetic phase transition process induced by femtosecond laser pulses can be mediated by the transient inplane magnetization state, resulting in the formation of topological skyrmions in real time and space domains. By combining experiments and micromagnetic simulations, a two-step process for creating skyrmions through laser pulse irradiation is proposed.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
R. Vilarinho, R. C. Vilao, H. Alberto, A. G. Marinopoulos, J. M. Gil, H. Luetkens, Z. Guguchia, M. Mihalik, M. Mihalik Jr, J. Agostinho Moreira
Summary: This study presents a comprehensive investigation into the spin dynamics and fluctuations in the ordered magnetic phases of the prototypical multiferroic material TbMnO3. Strong local magnetic-field disorder arising from the modulated Mn3+ spin arrangement and the effect of Tb3+ ordering at low temperatures is demonstrated through the temperature dependence of the dynamical and static components of the asymmetry. Evidence for an unusual magnetostructural coupling in the paramagnetic phase of TbMnO3 is provided using muon spin spectroscopy. The temperature dependence of the magnetic susceptibility in the paramagnetic phase is attributed to this magnetostructural coupling, likely involving oxygen displacements.
Article
Chemistry, Physical
J. Cwik, Y. Koshkid'ko, M. Malecka, B. Weise, M. Krautz, A. Mikhailova, N. Kolchugina
Summary: In-depth investigations were conducted on the magnetocaloric properties of polycrystalline Tb1-xHoxNi2 intermetallic compounds, revealing differences in magnetic entropy change and adiabatic temperature change among compounds with different compositions. The impact of holmium content on the magnetic and magnetocaloric properties of Laves-phase compounds was discussed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
J. Cwik, Y. Koshkid'ko, K. Nenkov, E. Tereshina-Chitrova, N. Kolchugina
Summary: The study focused on the magnetic entropy change and thermodynamic properties of polycrystalline pseudo-binary Tb1-xErxNi2 solid solutions, with emphasis on Er substitution for Tb causing changes in crystal structure. It was found that the substitution of Er for Tb resulted in a decrease in the ordering temperature of the pseudo-binary compounds, leading to an increase in the maximum magnetic entropy change.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Piotr Konieczny, Stanislaw M. Dubiel
Summary: The magnetic phase diagram of ?-Fe68V32 has been determined through ZFC/FC magnetization measurements, revealing a re-entrant character of magnetism and the presence of a spin-glass phase. The quantitative analysis of critical exponents using mean-field theory and Kouvel-Fisher approach showed consistency with the Gabay-Toulouse model.
Article
Chemistry, Multidisciplinary
Jakob Reichstein, Stephan Muessig, Hannes Bauer, Susanne Wintzheimer, Karl Mandel
Summary: This study introduces a maximum-temperature indicator based on micrometer-sized supraparticles with magnetic readout, which autonomously records temperature events. The indicator can obtain valuable temperature information inside bulk materials, even in dark and opaque macroscopic objects, with high sensitivity and fast response time.
ADVANCED MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Ali Ghoreyshi, Douglas A. Saunders, Chris J. Rea
Summary: Finite-size scaling is used to study the erasure mechanism in heat-assisted magnetic recording (HAMR) by numerically and experimentally evaluating predicted scaling equations with the write current-assist percentage (WCAP) method. Results show the scaling behavior of erasure temperature with different applied field values and provide estimates for the anisotropy field and critical exponent. The Stoner-Wohlfarth model is found to be an accurate approximation for the erasing process in FePt media.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Materials Science, Multidisciplinary
V. A. Stephanovich, E. Kirichenko, G. Engel, Yu G. Semenov, K. W. Kim
Summary: Theoretical analysis reveals that magnetic ions randomly distributed in a 2D semiconductor system can generate ferromagnetic long-range order. The discrete symmetry of the 2D Ising model of spin-spin interaction is crucial in this phenomenon, and fluctuations in molecular field play a key role in achieving ferromagnetism. The proposed theoretical model describes magnetization and phase transition temperature in terms of a single parameter, the chemical potential, and suggests a pathway to achieve high T-c and control magnetic properties externally.
Article
Physics, Applied
Rowan C. Temple, Mark C. Rosamond, Jamie R. Massey, Trevor P. Almeida, Edmund H. Linfield, Damien McGrouther, Stephen McVitie, Thomas A. Moore, Christopher H. Marrows
Summary: The B2-ordered alloy FeRh undergoes a metamagnetic phase transition at a critical temperature of around 380K, which can be triggered by various means. Research has shown that a phase boundary controlled by a doping gradient in a nano-pillar can be shifted by an electrical current, leading to memristive properties in resistive changes, suggesting potential applications in memory cells or artificial synapses in neuromorphic computing.
APPLIED PHYSICS LETTERS
(2021)
Editorial Material
Nanoscience & Nanotechnology
Christopher H. Marrows
Editorial Material
Physics, Applied
Laura J. J. Heyderman, Julie Grollier, Christopher H. H. Marrows, Paolo Vavassori, Dirk Grundler, Denys Makarov, Salvador Pane
APPLIED PHYSICS LETTERS
(2021)
Editorial Material
Chemistry, Physical
Christopher H. Marrows
Summary: A significant spin-orbit interaction is introduced in a purely silicon heterostructure and can be adjusted by applying a gate voltage.
Article
Physics, Multidisciplinary
Kevin J. A. Franke, Colin Ophus, Andreas K. Schmid, Christopher H. Marrows
Summary: Through micromagnetic simulations and analytical modeling, it has been found that Neel walls can be formed even in the absence of a Dzyaloshinskii-Moriya interaction, but with uniaxial in-plane magnetic anisotropy. The ability to switch between Bloch and Neel walls can be achieved via modulation of both in-plane and perpendicular magnetic anisotropy, opening up possibilities for electric field control of domain wall type with small applied voltages.
PHYSICAL REVIEW LETTERS
(2021)
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
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.
Review
Materials Science, Multidisciplinary
Khulaif Alshammari, Eloi Haltz, Mohammed Alyami, Mannan Ali, Paul S. Keatley, Christopher H. Marrows, Joseph Barker, Thomas A. Moore
Summary: In this study, the temperature dependence of the DMI in Pt/CoFeB/Ir and Pt/CoB/Ir multilayers was measured using static domain imaging. Key parameters were determined and scaling laws for Ku and D with magnetization were established. The scaling of Ku was consistent with Callen-Callen theory, while the scaling of D was found to be similar to the theoretically predicted scaling of A (<^>1.8).