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On the basis of Brown's static equations of micromagnetics, the uniaxial polarization of the scattered neutron beam of a bulk magnetic material is computed. The approach considers a Hamiltonian that takes into account the isotropic exchange interaction, the antisymmetric Dzyaloshinskii-Moriya interaction, magnetic anisotropy, the dipole-dipole interaction and the effect of an applied magnetic field. In the high-field limit, the solutions for the magnetization Fourier components are used to obtain closed-form results for the spin-polarized small-angle neutron scattering (SANS) cross sections and the ensuing polarization. The theoretical expressions are compared with experimental data on a soft magnetic nanocrystalline alloy. The micromagnetic SANS theory provides a general framework for polarized real-space neutron methods, and it may open up a new avenue for magnetic neutron data analysis on magnetic microstructures.
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http://dx.doi.org/10.1107/S1600576722003508 | DOI Listing |
Nano Lett
September 2025
Department of Physics and Astronomy, University of Nebraska─Lincoln, Lincoln, Nebraska 68588, United States.
In this study, using a set of scanning probe microscopy techniques, we investigate the electronic properties of the domain walls in the layered ferroelectric semiconductor of the transition metal oxide dihalide family, NbOI. Although the uniaxial ferroelectricity of NbOI allows only 180° domain walls, the pristine 2D flakes, where polarization is aligned in-plane, typically exhibit a variety of as-grown domain patterns outlined by the electrically neutral and charged domain walls. The electrically biased probing tip can modify the as-grown domain structures.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada.
Order parameters provide a useful qualitative and quantitative description of the distribution of molecules in ordered materials as they are independent of the shape of the orientation distribution. For samples that exhibit uniaxial ordering with no twist preference, extracting ⟨P2⟩ from polarized IR absorption data is common and obtaining ⟨P2⟩ and ⟨P4⟩ from Raman data has also been well-described. However, such an approach is not routine in the analysis of surface sum-frequency generation (SFG) spectra.
View Article and Find Full Text PDFNanoscale Horiz
August 2025
Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control for Aerospace Structures and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Engineering piezo-/flexo-electricity and flexomagnetism in two-dimensional (2D) materials beyond the best-known graphene and transition metal dichalcogenides has potential for accelerating micro- and nano-electromechanical system applications. Herein, using first-principles calculations, we demonstrate cobalt mono-telluride (CoTe) monolayer as an outstanding candidate for achieving large piezoelectric, flexoelectric and flexomagnetic responses down to the monolayer limit. The CoTe monolayer is found to be a semiconductor with a sizable bandgap of 0.
View Article and Find Full Text PDFInorg Chem
September 2025
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China.
Achieving valley polarization in altermagnets holds crucial significance for advancing the field of valleytronics. In this study, the Mg(FeN) monolayer is predicted as an altermagnet semiconductor with an in-plane magnetic anisotropy. Moreover, a pair of energy-degenerate valleys occurs in the present Mg(FeN) monolayer, which is connected by the crystalline symmetry.
View Article and Find Full Text PDFIt is shown that a Bessel beam with initial circular polarization, propagating through an optically active medium devoid of linear birefringence, generates an optical vortex on the axis in the orthogonally polarized component. The possibility of mutual transformation of beams with radial and azimuthal polarization distributions in a medium with pure optical activity is presented. It is proved that under a weak external perturbation of a medium with pure optical activity and linear birefringence, the isotropic point is destroyed.
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