Article
Chemistry, Multidisciplinary
James P. Durrant, Benjamin M. Day, Jinkui Tang, Akseli Mansikkamaki, Richard A. Layfield
Summary: Replacing the ligands in dysprosium single-molecule magnets with a different type leads to larger energy barriers to magnetization reversal. The distances between the ligands in the new complexes suggest a different crystal field splitting. Theoretical analysis shows that the magnetic axes in the ground Kramers doublets are oriented towards the new ligands. Introducing new parameters allows for comparisons between different single-molecule magnets, indicating the potential for improved performance in the new system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Physics, Multidisciplinary
Linjie Liu, Weijin Chen, Yue Zheng
Summary: In this study, researchers discovered a flexomagnetic effect and Hall effect in synthetic antiferromagnetic systems, and proposed the connection between these effects and the topological structures in the system. These findings provide new insights for research in related fields.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Hyeon-Kyu Park, Sang-Koog Kim
Summary: The study theoretically explored the ultrafast propagations of spin waves in antiferromagnetic Bloch-type domain walls and found that the dispersive relation of these spin waves shows extremely high group velocity without any forbidden gap. The results offer guidance for the development of ultrafast information signal processing in nanoscale magnonic circuits composed of antiferromagnetic domain walls.
Article
Materials Science, Multidisciplinary
B. B. Krichevtsov, S. M. Suturin, A. M. Korovin, A. K. Kaveev, V. E. Bursian, J. L. F. Cunado, N. S. Sokolov
Summary: Magnetization reversal in as-grown and annealed NiFe2O4 / SrTiO3(001) epitaxial heterostructures prepared by laser molecular beam epitaxy (LMBE) has been studied using magneto-optical technique. The hysteresis loops of polarization plane rotation and ellipticity measured in different geometries are influenced by symmetric and antisymmetric components, as well as quadratic and linear contributions of magnetization. Narrow and strong FMR lines are observed in structurally perfect samples.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
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
Physics, Applied
J. Li, P. van Nieuwkerk, M. A. Verschuuren, B. Koopmans, R. Lavrijsen
Summary: This article explores a fast and cost-effective fabrication method for the production and characterization of monodisperse magnetic nanoplatelets. The influence of size on magnetic properties is analyzed. The results show that substrate conformal imprint lithography allows for efficient large-scale platelet fabrication.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Daisy O'Mahoney, Sanyum Channa, Xin Yu Zheng, Arturas Vailionis, Padraic Shafer, Alpha T. N'Diaye, Christoph Klewe, Yuri Suzuki
Summary: Developed epitaxial spinel structure ferrite thin films of Li-0.5(AlxFe2.5-x)O-4 with ultra-low magnetic damping. Al substitution tunes saturation magnetization and in-plane magnetic anisotropy while maintaining excellent epitaxy and low damping. Element-specific x-ray magnetic circular dichroism measurements confirm magnetism originates from Fe3+ cations occupying octahedral sites.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Yuki K. Wakabayashi, Shingo Kaneta-Takada, Yoshiharu Krockenberger, Yoshitaka Taniyasu, Hideki Yamamoto
Summary: Epitaxial strain in SrRuO3 films directly influences their physical properties, offering an opportunity to tune the functionalities for electronic and spintronic devices. This study demonstrates wide-range control of electrical and magnetic properties in high-quality SrRuO3 films through epitaxial strain. The results provide guidelines for designing SrRuO3-based heterostructures for device applications.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Hao Zhao, Run Cheng, Quan-Hui Liu
Summary: This study presents a theoretical investigation and numerical simulations of the dynamics of domain walls in a curved nanowire with torsion in an antiferromagnetic environment. The equations of motion for the antiferromagnetic domain wall are derived, revealing that the curvature induces the Dzyaloshinskii-Moriya interaction and the torsion induces an anisotropy term, both of which drive the domain wall in opposite directions in a stable state.
RESULTS IN PHYSICS
(2023)
Article
Physics, Applied
Deyuan Lyu, Delin Zhang, Daniel B. Gopman, Yang Lv, Onri J. Benally, Jian-Ping Wang
Summary: In this study, perpendicular magnetic tunnel junctions (pMTJs) with synthetic antiferromagnetic (SAF) free layers were designed and fabricated. The magnetization dynamics of the SAF free layer were characterized, and a transition of the magnetic configuration at small device sizes was observed. The impact of the operating current on the offset field was also investigated. These findings provide insights for improving the material properties and device performance of SAF-pMTJs for ultrafast, ultralow-power consumption spintronic devices.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Christopher S. Perreault, Yogesh K. Vohra, Antonio M. dos Santos, Jamie J. Molaison
Summary: Neutron diffraction was used to study the magnetic ordering of Dysprosium (Dy) under high pressures and low temperatures. It was found that magnetic ordering occurred in the hexagonal close-packed, alpha-samarium, and double hexagonal close-packed phases of Dy, and previously undetected magnetic superlattice reflections were observed.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
R. A. Ribeiro, S. L. Bud'ko, L. Xiang, D. H. Ryan, P. C. Canfield
Summary: Single crystals of La2Ni7 exhibit antiferromagnetic phase transitions at low temperatures, with anisotropic properties. The results suggest that the antiferromagnetic order and ferromagnetic component in this material are associated with very small, itinerant moments.
Article
Instruments & Instrumentation
M. Slezak, H. Nayyef, P. Drozdz, W. Janus, E. Swierkosz, M. Szpytma, M. Zajac, A. Koziol-Rachwal, T. Slezak
Summary: We investigated the magnetic properties of epitaxial CoO(111)/Fe(110) and NiO(111)/Fe(110) bilayers by combining X-ray magnetic linear and circular dichroism with magnetooptic Kerr effect measurements. Our results show that in both cases, the ferromagnetic sublayer plays a dominant role and determines the magnetic state of the neighboring antiferromagnet, although different interaction scenarios are observed. In CoO/Fe bilayers, the antiferromagnetic spins are frozen and their orientation is imprinted by the magnetization of the Fe layer. On the other hand, in NiO/Fe bilayers, the antiferromagnetic spins are rotatable and always follow the reorientation of the Fe magnetization.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Physics, Applied
John Nance, Kawsher A. Roxy, Sanjukta Bhanja, Greg P. Carman
Summary: This study investigates a multiferroic antiferromagnet as a high-speed artificial synapse in artificial intelligence applications using a finite-element model coupling micromagnetics and dynamic strain. It successfully programs two intermediate states using strain pulses and finds the minimum programming time to be around 0.3 ns.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Gabriele Baglioni, Makars Siskins, Maurits Houmes, Martin Lee, Dong Hoon Shin, Samuel Manas-Valero, Eugenio M. Coronado, Yaroslav Blanter, Herre S. J. G. van der Zant, Peter Steeneken
Summary: Magnetostrictive coupling has become a sensitive method for studying magnetism in 2D materials by mechanical means. In this study, we optothermally modulate the magnetization in antiferromagnetic 2D material membranes to induce a high-frequency magnetostrictive driving force. The thermo-magnetostrictive effect near the critical temperature of magnetostrictive 2D materials provides a route for more efficient actuation of nano-magnetomechanical devices and studying the coupling among magnetic, mechanical, and thermodynamic degrees of freedom.
Article
Nanoscience & Nanotechnology
Yaoqiao Hu, Darrell Schlom, Suman Datta, Kyeongjae Cho
Summary: This article introduces an engineering method to improve the band gap and hole mobility of SnO by interlayer intercalation. The study found that the interlayer stacking spacing change can increase the band gap and hole mobility of SnO, and small molecules such as NH3 and CH4 can be used as interlayer intercalants.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Christo Guguschev, Carsten Richter, Mario Bruetzam, Kaspars Dadzis, Christian Hirschle, Thorsten M. Gesing, Michael Schulze, Albert Kwasniewski, Juergen Schreuer, Darrell G. Schlom
Summary: In this study, we demonstrate the growth of large (Mg,Zr):SrGa12O19 single crystals and use X-ray imaging techniques to analyze their structural and chemical homogeneity. We developed a lab-based X-ray diffraction imaging technique that can detect subtle variations in lattice parameters and lattice tilts attributed to changes in chemical composition and resulting elastic deformation. Micro X-ray fluorescence mapping was used to verify the relationship between unit-cell dimensions and composition. The SGMZ crystals exhibited good structural quality and homogeneity, making them suitable for high-quality substrate preparation.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Pedram Abbasi, Nozomi Shirato, Rishi E. Kumar, Isabel V. Albelo, Matthew R. Barone, Deniz N. Cakan, Ma. de la Paz Cruz-Jauregui, Sarah Wieghold, Darrell G. Schlom, Volker Rose, Tod A. Pascal, David P. Fenning
Summary: In this study, the role of polarization on the surface structure and chemistry of a model ferroelectric BaTiO3 thin film was investigated using synchrotron X-ray scanning tunneling microscopy (SX-STM) and computational absorption spectroscopy. The results showed that polarization switching increased the X-ray absorption intensity and modulated the surface structures. Theoretical calculations supported these findings and provided evidence for the effect of polarization switching on the binding strength with molecular O2. This study advances the understanding of the surface chemistry and electronic structure of ferroelectrics, which can inform the design of interfaces with tailored properties.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Applied
Prosper Ngabonziza, Jisung Park, Wilfried Sigle, Peter A. van Aken, Jochen Mannhart, Darrell G. Schlom
Summary: We have developed a synthetic route to achieve high electron mobility at room temperature in La:BaSnO3/SrZrO3 heterostructures grown on various oxide substrates. The room-temperature mobilities obtained were 157, 145, and 143 cm(2) V(-1) s(-1) for heterostructures grown on DyScO3 (110), MgO (001), and TbScO3 (110) crystalline substrates, respectively. This was achieved by growing a SrZrO3 buffer layer at high temperature using pulsed laser deposition to reduce dislocation density, followed by the epitaxial growth of a La:BaSnO3 active layer using molecular-beam epitaxy. The results provide a promising pathway for achieving high mobility in buffered La:BaSnO3 films on oxide substrates with lattice mismatches.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Stephanie D. Matson, Jiaxin Sun, Jason J. Huang, Don J. Werder, Darrell G. Schlom, Andrej Singer
Summary: Renewable energy sources such as solar and wind are necessary to combat global warming, but their intermittent generation requires large-scale grid energy storage, unlike coal-based power plants. Sodium-ion batteries show promise, but their structural rearrangements during intercalation make them less durable. In this study, we synthesized epitaxial NaxCoO2 films that allow electrochemical extraction of sodium ions, providing a foundation for future studies on interfaces and structural changes in sodium-ion batteries.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Coatings & Films
Tobias Schwaigert, Salva Salmani-Rezaie, Matthew R. Barone, Hanjong Paik, Ethan Ray, Michael D. Williams, David A. Muller, Darrell G. Schlom, Kaveh Ahadi
Summary: Strain-engineering is used to tune the instabilities of incipient ferroelectrics. High-quality KTaO3 thin films are grown by molecular-beam epitaxy. Excess potassium and a combination of ozone and oxygen are supplied with the TaO2 (or tantalum) molecular beams to grow the films with atomically abrupt interfaces. Atomic force microscopy reveals atomic steps at the film surface. Reciprocal space mapping demonstrates coherent strain to the substrates when the films are thin enough.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Materials Science, Coatings & Films
Thomas J. Smart, Felix V. E. Hensling, Dong Yeong Kim, Lena N. Majer, Y. Eren Suyolcu, Dominik Dereh, Darrell G. Schlom, Debdeep Jena, Jochen Mannhart, Wolfgang Braun
Summary: This work investigates the behavior of aluminum sources in oxide thermal laser epitaxy and identifies two distinct operating regimes. At high laser-beam fluences, the source emits reproducible fluxes independent of oxygen pressure. At lower beam fluences, the flux increases with increasing oxygen pressure due to suboxide formation. The study demonstrates reproducible rate control over a wide range and highlights the advantages of thermal laser epitaxy over oxide molecular-beam epitaxy in handling aluminum sources.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Multidisciplinary
Huaixun Huyan, Zhe Wang, Linze Li, Xingxu Yan, Yi Zhang, Colin Heikes, Darrell G. Schlom, Ruqian Wu, Xiaoqing Pan
Summary: Defect engineering in perovskite thin films has received extensive attention due to their atomic-level modification and the design of novel nanostructures. However, three-dimensional defect-assisted nanostructures in thin film matrices usually have large misfit strains and unstable structures. In contrast, one- or two-dimensional defect-assisted nanostructures embedded in thin films can sustain large misfit strains without relaxation, making them suitable for defect engineering in perovskite thin films.
Review
Physics, Multidisciplinary
Javier Junquera, Yousra Nahas, Sergei Prokhorenko, Laurent Bellaiche, Jorge iniguez, Darrell G. Schlom, Long-Qing Chen, Sayeef Salahuddin, David A. Muller, Lane W. Martin, R. Ramesh
Summary: The past decade has witnessed significant progress in understanding emergent topological polar textures in oxide nanostructures, including vortices, skyrmions, merons, hopfions, dipolar waves, and labyrinthine domains. The discovery of low-dimensional ferroelectric oxide nanostructures has altered the perceived energy cost associated with the formation of these structures, allowing for manipulation of order parameters. This review provides a historical context, scientific description, and discussion of the potential applications and future challenges in this field.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Multidisciplinary Sciences
Xiaoyu Zhang, Grant Fitez, Shayaan Subzwari, Nicholas S. Bingham, Ioan-Augustin Chioar, Hilal Saglam, Justin Ramberger, Chris Leighton, Cristiano Nisoli, Peter Schiffer
Summary: We investigated a model nanomagnetic array where the behavior of magnetic moments is visibly affected by constraints imposed by the system's topology. Magnetic excitations in this system form thermally active one-dimensional strings, and their motion can be observed in real time.
Article
Nanoscience & Nanotechnology
Nathaniel J. Schreiber, Ludi Miao, Berit H. Goodge, Lena F. Kourkoutis, Kyle M. Shen, Darrell G. Schlom
Summary: Molecular-beam epitaxy enables the combination of ultrathin functional materials to create emergent phenomena at the interface. In this study, a model heterostructure with engineered Berry curvature is synthesized to reproduce a hump-like feature, commonly attributed to the presence of skyrmions. However, despite the clear hump, no evidence of skyrmions is found.
Editorial Material
Psychology, Biological
Diego Gomez-Zara, Peter Schiffer, Dashun Wang
NATURE HUMAN BEHAVIOUR
(2023)
Article
Physics, Applied
Emily Amonette, Prabin Dulal, Dylan Sotir, Matthew Barone, Darrell Schlom, Nikolas J. Podraza
Summary: TbScO3 is a wide bandgap semiconductor used in charge trap memory devices and as an alternate gate dielectric. It has an orthorhombic crystal structure, leading to optical anisotropy. Generalized ellipsometric spectra were measured for different orientations of TbScO3 single crystals, revealing a direct bandgap at 6.50 eV and critical point transitions above the gap at 6.99, 7.14, 7.16, 7.21, and 7.42 eV.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Xiaoyu Zhang, Ioan-Augustin Chioar, Grant Fitez, Anthony Hurben, Michael Saccone, Nicholas S. Bingham, Justin Ramberger, Chris Leighton, Cristiano Nisoli, Peter Schiffer
Summary: The collective behavior of interacting arrays of nanomagnetic tripods is studied. Experimental data show that triangular lattice arrays form a tripod ice with charge ordering among the effective vertex magnetic charges, similar to artificial kagome spin ice. The interacting tripods have effective moments that act as emergent local variables, with connections to the Potts and clock models. Our results provide a new approach to study the collective behavior of nonbinary moments that is not available in other physical systems.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Chunqiang Xu, Caitlin Carnahan, Heda Zhang, Milos Sretenovic, Pengpeng Zhang, Di Xiao, Xianglin Ke
Summary: In this study, the authors observed a large magnetothermal conductivity and thermal Hall effect in a two-dimensional van der Waals antiferromagnet FeCl2. The magnetothermal conductivity reached over -700%, indicating strong magnon-phonon coupling. Additionally, an appreciable thermal Hall signal was found, which changed sign with the spin-flip transition from the antiferromagnetic state to the polarized ferromagnetic state. Theoretical calculations suggested that besides the Berry curvature induced at the anticrossing points of the hybridized magnon and acoustic phonon modes of FeCl2, other mechanisms were needed to explain the magnitude of the observed thermal Hall effect.
