Comprehending the interaction between geometry and magnetism in three-dimensional (3D) nanostructures is important to understand the fundamental physics of domain wall (DW) formation and pinning. Here, we use focused-electron-beam-induced deposition to fabricate magnetic nanohelices with increasing helical curvature with height. Using electron tomography and Lorentz transmission electron microscopy, we reconstruct the 3D structure and magnetization of the nanohelices. The surface curvature, helical curvature, and torsion of the nanohelices are then quantified from the tomographic reconstructions. Furthermore, by using the experimental 3D reconstructions as inputs for micromagnetic simulations, we can reveal the influence of surface and helical curvature on the magnetic reversal mechanism. Hence, we can directly correlate the magnetic behavior of a 3D nanohelix to its experimental structure. These results demonstrate how the control of geometry in nanohelices can be utilized in the stabilization of DWs and control of the response of the nanostructure to applied magnetic fields.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.nanolett.3c04172 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Terahertz Radiation Driven Nonlinear Transport Phenomena in Two-Dimensional Tellurene.
Nano Lett
December 2024
Physics Department, University of Regensburg, 93040 Regensburg, Germany.
Nonlinear electron transport induced by polarized terahertz radiation is studied in two-dimensional tellurene at room temperature. A direct current, quadratic in the radiation's electric field, is observed. Contributions sensitive to radiation helicity and polarization orientation as well as polarization independent current are found.
View Article and Find Full Text PDFNon-Hermitian Theory of Valley Excitons in Two-Dimensional Semiconductors.
Phys Rev Lett
December 2024
School of Physics and Electronics, Hunan University, Changsha 410082, China.
Electron-hole exchange interaction in two-dimensional transition metal dichalcogenides is extremely strong due to the dimension reduction, which promises valley-superposed excitonic states with linearly polarized optical emissions. However, strong circular polarization reflecting valley-polarized excitonic states is commonly observed in helicity-resolved optical experiments. Here, we present a non-Hermitian theory of valley excitons by incorporating optical pumping and intrinsic decay, which unveils an anomalous valley-polarized excitonic state with elliptically polarized optical emission.
View Article and Find Full Text PDFInvestigating How Lysophosphatidylcholine and Lysophosphatidylethanolamine Enhance the Membrane Permeabilization Efficacy of Host Defense Peptide Piscidin 1.
J Phys Chem B
December 2024
Department of Applied Science, William & Mary, Williamsburg, Virginia 23185, United States.
Lysophospholipids (LPLs) and host defense peptides (HDPs) are naturally occurring membrane-active agents that disrupt key membrane properties, including the hydrocarbon thickness, intrinsic curvature, and molecular packing. Although the membrane activity of these agents has been widely examined separately, their combined effects are largely unexplored. Here, we use experimental and computational tools to investigate how lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE), an LPL of lower positive spontaneous curvature, influence the membrane activity of piscidin 1 (P1), an α-helical HDP from fish.
View Article and Find Full Text PDFExtension of sticholysins N-terminal α-helix signals membrane lipids to acquire curvature for toroidal pore formation.
Biochem Biophys Res Commun
January 2025
Center of Protein Studies, Faculty of Biology, Havana University, Havana, Cuba.
Sticholysin I and II (St I/II) belong to the actinoporins family; these proteins form pores in host cell membranes by binding their N-terminal segment to the membrane, leading to protein-lipid (toroidal) pores. Peptides derived from actinoporins pore-forming domains replicate their folding properties and permeabilizing effects. Despite the advances in understanding how these proteins and peptides mediate pore formation, the role of different N-terminal segments in inducing membrane curvature is still unclear.
View Article and Find Full Text PDFColloidal substrate-facilitated synthesis of gold nanohelices.
J Colloid Interface Sci
December 2024
Institute of Advanced Synthesis (IAS) and School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Centre for Advanced Materials, Nanjing Tech University, 30 Puzhu South Road, Nanjing 211816, PR China. Electronic address:
Helical nanostructures have unique optical and mechanical properties, yet their syntheses had always been quite challenging. Various symmetry-breaking mechanisms such as chiral templates, strain-restriction and asymmetric ligand-binding have been developed to induce the helical growth at nanoscale. In this work, with neither chiral ligands nor templates, gold (Au) nanohelices were synthesized via a facile wet-chemical method, through an asymmetric Active Surface Growth facilitated by colloidal silica nanoparticles (NPs).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!