We report magnetization and neutron scattering measurements down to 60 mK on a new family of Fe based kagome antiferromagnets, in which a strong local spin anisotropy combined with a low exchange path network connectivity lead to domain walls intersecting the kagome planes through strings of free spins. These produce unfamiliar slow spin dynamics in the ordered phase, evolving from exchange-released spin flips towards a cooperative behavior on decreasing the temperature, probably due to the onset of long-range dipolar interaction. A domain structure of independent magnetic grains is obtained that could be generic to other frustrated magnets.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.107.257205 | DOI Listing |
Small
January 2025
Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing, 100875, P. R. China.
Establishing the relationship between catalytic performance and material structure is crucial for developing design principles for highly active catalysts. Herein, a type of perovskite fluoride, NHMnF, which owns strong-field coordination including fluorine and ammonia, is in situ grown on carbon nanotubes (CNTs) and used as a model structure to study and improve the intrinsic catalytic activity through heteroatom doping strategies. This approach optimizes spin-dependent orbital interactions to alter the charge transfer between the catalyst and reactants.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.
Thick metamorphic buffers are considered indispensable for III-V semiconductor heteroepitaxy on large lattice and thermal-expansion mismatched silicon substrates. However, III-nitride buffers in conventional GaN-on-Si high electron mobility transistors (HEMT) impose a substantial thermal resistance, deteriorating device efficiency and lifetime by throttling heat extraction. To circumvent this, a systematic methodology for the direct growth of GaN after the AlN nucleation layer on six-inch silicon substrates is demonstrated using metal-organic vapor phase epitaxy (MOVPE).
View Article and Find Full Text PDFNat Commun
January 2025
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, 610065 Chengdu, China.
Dual-atom catalysts featuring synergetic dinuclear active sites, have the potential of breaking the linear scaling relationship of the well-established single-atom catalysts for oxygen reduction reaction; however, the design of dual-atom catalysts with rationalized local microenvironment for high activity and selectivity remains a great challenge. Here we design a bisalphen ladder polymer with well-defined densely populated binuclear cobalt sites on Ketjenblack substrates. The strong electron coupling effect between the fully-conjugated ladder structure and carbon substrates enhances the electron transfer between the cobalt center and oxygen intermediates, inducing the low-to-high spin transition for the 3d electron of Co(II).
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir Prelog Weg 2, 8093 Zurich, Switzerland.
Relaxation-induced dipolar modulation enhancement (RIDME) is a pulse EPR experiment originally designed to determine distances between spin labels. However, RIDME has several features that make it an efficient tool in a number of "nonconventional" applications, away from the original purpose of this pulse experiment. RIDME appears to be an interesting experiment to probe longitudinal electron spin dynamics, e.
View Article and Find Full Text PDFNano Lett
January 2025
Max Planck Institute for Solid State Research, Heisenbergstr. 1, Stuttgart, 70569, Germany.
Spin Hall nano-oscillators convert DC to magnetic auto-oscillations in the microwave regime. Current research on these devices is dedicated to creating next-generation energy-efficient hardware for communication technologies. Despite intensive research on magnetic auto-oscillations within the past decade, the nanoscale mapping of those dynamics remained a challenge.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!