Microwave thermal supercharging therapy enables selective tumor ablation via low-power radio frequency-responsive nanotopographies.

We develop a real-space framework for modelling magnetically confined states in two-dimensional quantum dots, which constitute a field of intense experimental and theoretical study in view of potential applications in quantum technology, directional electronics and magneto-sensing, for instance. The method integrates a Wilson-type finite-difference discretization leading to the Wilson Hamiltonian (WH), which enforces exact local U(1) gauge invariance on the lattice, with imaginary-time propagation (ITP) as an efficient and numerically stable eigensolver. This combination eliminates gauge-dependent artefacts that commonly arise when the vector potential directly features in the Hamiltonian and enables accurate treatment of arbitrary confinement potentials. Benchmark calculations on GaAs quantum dots with harmonic and Gaussian trapping potentials demonstrate sub-cm-1 agreement with analytical and variational benchmarks across a wide range of magnetic fields, including the Landau regime. The approach is further applied to quantum dots formed in monolayer phosphorene, where strongly anisotropic effective masses and confinement potentials give rise to characteristic field-dependent level shifts and reordering. In addition to the energies, we introduce quantitative parameters and examine the evolution of the corresponding wavefunctions, showing that the method accurately reproduces magnetic-field-induced contraction, nodal structures, and angular-momentum-driven radial reorganization. These results indicate that the WH-ITP method could be a robust and versatile tool for modelling magnetic confinement and electronic structure in two-dimensional quantum dots and related nanoscale materials.

Noise estimation and suppression in quantitative EMCD measurements.

Antiferromagnetic spintronics offers a transformative route toward high-density and ultrafast memory technologies. However, probing and manipulating spin dynamics in antiferromagnets remain highly challenging due to their nearly vanishing net magnetization and intrinsically complex magnetic structures. A long-standing puzzle in this field is the anomalous phase shift observed in spin Hall magnetoresistance (SMR) measurements, which has recently been attributed to altermagnetic spin splitting effect. In this work, we demonstrate that such an anomalous phase shift also emerges in nonaltermagnetic materials. By investigating the microscopic interplay between the Néel order and canted spin polarization in fully epitaxial BiFeO3/SrRuO3 heterostructures, we provide a comprehensive explanation for this intriguing phenomenon. Through a combination of angle-dependent transport measurements and first-principles calculations, we show that the SMR signal is governed by two competing mechanisms: a robust contribution originating from the antiferromagnetic Néel vector (NSMR) and a highly temperature-sensitive component arising from ferromagnet-like canted spin polorization (PSMR) which is constrained by the symmetry-allowed Dzyaloshinskii-Moriya coupling. We further reveal that the elusive phase shift stems from the rapid enhancement of the canted spin polarization at low temperatures, which fundamentally alters the symmetry of spin-current absorption. Our findings establish a unified physical framework for disentangling complex spin interactions in antiferromagnetic materials.

Surface-supported single rare-earth atom magnets represent an ultimate limit of magnetic miniaturisation, where information storage is reduced to the scale of an individual atom. At this limit, magnetism is intrinsically quantum mechanical and governed by the interplay of strong electron correlations, crystal-field effects, and spin-orbit coupling within the localized 4f shell. In this review, we summarise and analyse recent theoretical advances in the description of rare-earth adatoms, with particular emphasis on approaches that go beyond conventional static mean-field DFT+U , which may exhibit multiple metastable solutions and treat magnetic anisotropy in a semiclassical manner. We discuss a predictive framework combining relativistic density functional theory with an Anderson impurity model treatment of the multiconfigurational 4f shell (DFT+U (HIA)), enabling a consistent description of strong correlations, multiplet structure, and quantum tunnelling effects induced by transverse crystal-field terms.As a representative case, we review the electronic structure and magnetic anisotropy of Dy adatoms on insulating MgO and spin-polarised graphene/Ni substrates. For Dy@MgO, an apparent perpendicular anisotropy is strongly reduced by quantum tunnelling driven by transverse crystal-field terms, effectively shifting the easy axis towards the surface plane. In contrast, Dy@Gr/Ni(111) realises a robust perpendicular magnetic configuration at the single-atom level. Here, the large positive magnetic anisotropy energy arises from the interplay of crystal-field splitting and strong spin-orbit coupling within the Dy 4f shell, further reinforced by the exchange field generated by the ferromagnetic Ni substrate.We argue that Dy@Gr/Ni(111) may be viewed as a limiting atomic-scale analogue of perpendicular synthetic heterostructures used in magnetic memory technologies, where exchange coupling and strong anisotropy are engineered to stabilise nanoscale bits. The insights gained from these studies establish a microscopic design principle for achieving thermally robust magnetic anisotropy at the ultimate scaling limit and highlight the broader potential of strongly correlated rare-earth adatoms for atomic-scale spintronic applications.

Many nanoscale magnetic imaging techniques are constrained by the maximum magnetic field that can be applied during measurements, due to geometrical limitations or interactions with the probe or the detected signal (e.g., electrons). Here, it is demonstrated that sample-integrated metamaterial-inspired magnetic flux concentrators (MFCs) locally amplify magnetic fields, allowing observation of magnetization processes beyond instrumental limits. Micrometer-sized MFCs fabricated directly on the samples are tested in photoemission electron microscopy experiments employing X-ray magnetic circular dichroism as magnetic contrast mechanism. At low applied fields, substantial amplification factors enable observation of magnetization reversal in a chain of magnetite nanoparticles synthesized by magnetotactic bacteria at an applied field of 8mT, substantially smaller than the ∼50mT predicted by simulations in the absence of MFCs. At higher fields, the field enhancement extends the accessible field range by a factor of five, enabling for the first time, imaging of the field-dependent magnetic domain structure evolution of an isolated giant magnetofossil. Finally, we show how MFC geometry and material parameters can be tuned to optimize performance considering sample and experimental constraints, providing a tunable and broadly applicable strategy for extending the accessible field range in a wide variety of nanoscale magnetic imaging techniques.

The contrasting crystal and magnetic structures of four related iron oxide chalcogenides are reported. Ae2FeO3CuCh (Ae = Ca, Sr; Ch = S, Se) all crystallize in the Sr2GaO3CuS structure with alkaline earth iron oxide layers containing double layers of linked FeO5 square pyramids containing Fe3+ ions separated by antifluorite-type [Cu2Ch2]2- layers. Structural distortions occur below room temperature when the small Ca2+ ions are present, and these involve cooperative tilting of the FeO5 square pyramids. Magnetic reflections present in the diffraction patterns can be indexed using either √2a × √2a × c or √2a × √2a × 2c expansions of the nuclear cell with nearest-neighbor Fe3+ moments coupling antiferromagnetically and with temperature-dependent orientations relative to the crystallographic directions. The magnetic structures of these compounds are subtly different in detail, partly on account of the low directional preference of the high-spin d5 Fe3+ moments.

Investigation of a Transient Highly Twisted Magnetic Structure Using NVST, CHASE, and SDO Observations

A series of volatile cobalt(II) and nickel(II) N,N'-dialkyl-bis(β-dialdiminato) complexes of stoichiometry M[RN(CH)3NR]2 (where R = methyl, ethyl, iso-propyl, or tert-butyl) have been prepared and characterized. NMR, IR, and UV-vis spectra are reported, along with their magnetic properties and crystal structures. IR and crystallographic data support the conclusion that all these complexes contain divalent metal ions and closed-shell monoanionic ligands. NMR studies indicate that some spin density is delocalized directly into the π-orbitals of the β-dialdiminate ligand, as seen in other N,N'-diaryl and β-diketiminato compounds of cobalt(II) and nickel(II), and magnetic measurements afford magnetic moments that are larger than the spin-only values owing to orbital contributions to the moments. In the UV-Vis spectra, the higher energy spin-allowed d-d transition can be observed in the visible (or near visible) region. Overall, these new cobalt(II) and nickel(II) compounds are similar to their N,N'-diaryl and β-diketiminato analogues, but have lower molecular masses and thus are more volatile, making them potentially useful precursors for the chemical vapor deposition (CVD) of cobalt- or nickel-containing films.

Abstract The enriched 160 Gd isotope is an important target nucleus for the production of the next-generation β -emitting therapeutic nuclide 161 Tb. To address the limitation that the J = 2 → 2 → 1 → 0 polarization ionization path, although suitable for separating odd Gd isotopes with parallel linearly polarized lasers, cannot be used to enrich even Gd isotopes, we propose an efficient and highly selective ionization scheme for 160 Gd. Based on the density matrix theory, a general four-color, three-step ionization model was established by taking into account magnetic sublevel degeneracy and hyperfine structure. Numerical calculations of photoionization dynamics were performed to optimize laser parameters such as polarization, power density, and frequency detuning, with the aim of enhancing the ionization yield and isotopic abundance of 160 Gd. The results show that, in the absence of Doppler broadening, the ionization yield obtained with orthogonal linear polarization is higher than that obtained with parallel linear polarization in both three-color, three-step and four-color, three-step schemes. To maximize ionization yield, resonant excitation is required in the three-color, three-step scheme, whereas detuned excitation is needed in the four-color, three-step schemes to mitigate the population trapping effect. When Doppler broadening is taken into account, the selective photoionization performance depends on the residual Doppler broadening and on the number of laser beams passing through the atomic vapor. The calculations indicate that the optimal ionization scheme, namely the four-color, three-step scheme with parallel linear polarization, detuned excitation, saturation power density, and a bandwidth of 0.5 GHz, can achieve a 160 Gd abundance exceeding 98% at a residual Doppler broadening of 0.45 GHz, thereby meeting the application requirements.

Intercalated van der Waals (vdW) magnets have attracted growing interest owing to their rich and highly tunable magnetic properties and their promise for ultracompact spintronic applications. A remarkable example is self-intercalated chromium tellurides (Cr1+δTe2), in which spatially ordered chromium atoms occupy the vdW gaps, yielding a variety of known compounds (e.g., Cr1.25Te2, Cr1.33Te2, and Cr1.5Te2) that host distinct and intriguing magnetic states. In this work, we uncover the existence of hidden, ordered self-intercalated phases that form spontaneously along with a twisted Cr1.5Te2 phase in chromium telluride nanoflakes grown by chemical vapor deposition. Using wide-field and scanning diamond nitrogen-vacancy center (NV) magnetometry, we unveil intricate magnetic structures in the chromium telluride flakes at the nanoscale and above room temperature. In a small nanoflake, the magnetization prefers an in-plane orientation in its interior with strong anisotropy but is tilted out of plane at the edges. In a large nanoflake, we observe complex magnetic profiles indicating the possible formation of nontrivial localized topological structures. Our work demonstrates the versatility of self-intercalation beyond known phases and the rich magnetic properties in a model vdW magnet, highlighting its great potential for room-temperature spintronic applications.

Developing stable water-based ferrofluids with efficient magnetic heating remains a key challenge for biomedical hyperthermia. In this work, we functionalize Fe₃O₄ nanoparticles with surfactants of different chemical nature namely ethylenediaminetetraacetic acid (EDTA), ethanolamine and betaine and examine the role of surface chemistry on colloidal stability and heating performance in aqueous media. HRTEM study on these samples reveals particle sizes of ~10-13 nm, indicating monocrystalline nanoparticles with a surface coating. We confirm the successful functionalization with different functional groups such as carboxylate, amine and zwitterionic groups by FTIR, TGA, and XPS analysis. Zeta potential values ranging from -22.5 to -46.2 mV indicate negatively charged surfaces governed by Fe-O -groups and surfactant functionalities which ensures electrostatic stabilization in water. VSM measurements confirm superparamagnetic behavior with saturation magnetization of 55-63 emu g⁻¹ indicating that the magnetic core structure is preserved. Among the studied systems, EDTA-functionalized Fe₃O₄ exhibits exceptional long-term stability, retaining its ferrofluid state without sedimentation for over one year. This stable dispersion correlates with superior magnetic heating performance, achieving the highest SAR (~245 W g⁻¹ at 0.5 mg mL⁻¹). These results demonstrate that surface functionalization plays a critical role in stabilizing aqueous ferrofluids, enhance hyperthermia efficiency and provide a practical basis for designing biocompatible magnetic nanofluids.

We examine the magnetic properties of ∼23 nm single domain nanocubes and ∼200 nm multidomain iron oxide nanoparticles that are surface functionalized with poly(L- or D-phenylalanine) chiral brushes of variable length. Interestingly, the larger nanoparticles manifest a remanent magnetization in all directions, i.e., display monopole-like or hedgehog behaviour that depends on the handedness of the brush. Conversely, no such response is observed in the smaller nanoparticles. The emergent monopole-like magnetic properties are attributed to the chiral-induced spin selectivity effect acting on the magnetic domain structure, single vs. multidomain, to imprint a magnetization bias on the nanoparticles. Collectively, this study reveals a facile approach for the formation of hedgehog magnetic nanoparticles and outlines features necessary for their formation.

Designing compact, high-gain antennas at 400 MHz is challenging due to large size, narrow bandwidth, and low efficiency. This work proposes an interaction-driven Artificial Magnetic Conductor-Defected Ground Structure (AMC-DGS) microstrip antenna for subsurface communication. The design exploits electromagnetic interaction between the slot-type DGS, radiating patch, and AMC surface with spacer layer for performance enhancement. The DGS functions not only for impedance tuning or to attain polarization purity but also as an active radiator, enabling current redistribution and higher order mode perturbation. This interaction, combined with composite superposed mode (CSM) excitation and orthogonal slot radiation, achieves a 400 MHz band (379–419 MHz) with 10.2% bandwidth and 6.5 dBi peak gain. Additionally, a higher-order mode generates a second band at 700 MHz (700–714 MHz) with 2% bandwidth and 6.1 dBi gain. The antenna maintains stable broadside radiation with efficiencies of 98% and 70% at 400 MHz and 700 MHz, respectively. The proposed AMC-DGS antenna provides a compact, dual-band solution for subsurface sensing, Wireless Underground Sensor Networks (WUSN), Internet of Underground Things (IoUT), Ground Penetrating Radar (GPR), and other low-frequency communication systems.

Fe3GaTe2 is a van der Waals (vdW) ferromagnet with a Curie temperature TC ranging from 350 to 380 K, followed upon cooling by a ferrimagnetic transition near room temperature. Substituting Fe with Co was previously reported to induce antiferromagnetism (AFM) at a Co fraction-dependent Néel temperature TN. In this work, we confirm the overall phase diagram of the Fe3-xCoxGaTe2 series as a function of x and temperature via magnetization and electrical transport measurements. For x ⩾ 0.6, the Hall effect is observed to mimic the magnetization as the AF ground state is suppressed by the external magnetic field via a metamagnetic transition, thus displaying an anomalous Hall response. At low temperatures, we also observe a pronounced topological Hall signal peaking at μ0H = 4 T, or within the metamagnetic transition region of fields. This observation points to the presence of magnetic field-induced chiral spin textures, such as skyrmions, upon approaching magnetization saturation. Magnetic force microscopy (MFM) reveals the emergence of nearly circular magnetic domains, with diameters on the order of 100-200 nm, within the antiferromagnetic phase. A detailed analysis of the MFM images indicates that the topological Hall effect is closely linked to the field-induced stabilization of magnetic domain structures, likely exhibiting chiral textures. This observation suggests the possible formation of skyrmions already in the AFM phase, i.e., AFM skyrmions, that evolve into ferromagnetic (FM) ones upon increasing the magnetic field. Consequently, Co-doped Fe3GaTe2 might provide a platform to investigate the transformation of skyrmions, initially coupled antiferromagnetically into ferromagnetic ones, and to explore its impact on the topological and skyrmion Hall effects.

Two-dimensional MXenes are attractive materials because of their metallic conductivity, abundant surface terminations, and high aspect ratio, which can be coupled with organic molecules and magnetic structures to produce multifunctional architectures. Here, we engineered a diphenylthiocarbazone-grafted magnetic MXene, DTZ-Ti3C2@Fe3O4, through a stepwise synthesis of magnetic nanoparticles on Ti3C2 nanosheets and subsequent grafting of diphenylthiocarbazone covalently onto surface functional groups. This route yielded a hierarchically structured 2D hybrid, in which (i) Ti3C2 provided an extended, mechanically strong active scaffold, (ii) there were well-dispersed magnetic domains without shielding the MXene surface, and (iii) the immobilized diphenylthiocarbazone moieties were present as densely packed, multidentate soft-donor (N,S) chelation sites. This structure was used as an analytical tool to investigate the health risk assessment of heavy metal consumption. Under optimized conditions and acceptable figures of merit (detection limits of 0.085 ng mL-1 (Cd2+) and 0.87 ng mL-1 (Pb2+) with linear ranges of 0.3-40 µg L-1 and 3-80 µg L-1 and a preconcentration factor (PF) of 100), the concentration of heavy metals in food samples was quantified at trace levels and was directly used to calculatethe Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Total Target Hazard Quotient (TTHQ), and lifetime Cancer Risk (CR) using body-weight and consumption-rate scenarios. The results showed TTHQ < 1 and CR < 1 × 10-4 for Cd and Pb ions in the analyzed food samples. To the best of our knowledge, this study reports the first covalently grafted diphenylthiocarbazone-magnetic MXene tailored specifically for the trace-metal detection and quantitative health risk assessment of heavy metals and food safety evaluation. This report demonstrates that MXenes can serve as a practical analytical platform for population-relevant risk assessment and not merely trace detection.

Towards reliable electrical measurements of superconducting devices inside a transmission electron microscope.

Uniaxial stress is a promising method to tune magnetic frustration, allowing its effects to be studied in a precise way. In this work, uniaxial stress is applied to the triangular-lattice antiferromagnet PdCrO2. The Cr-Cr magnetic interaction is very sensitive to interatomic separation, so laboratory-achievable stress can induce substantial changes in magnetic structure. Results from three types of measurement are presented: x-ray diffraction, the stress-strain relationship, and neutron diffraction. The combined data show that the elastic moduli of PdCrO2are strongly affected by stress-induced changes in magnetic structure. A new, first-order stress-induced magnetic transition is observed, at which the lattice constant shrinks by 0.21%. The lattice stiffens dramatically across this transition: the Young's modulus increases by≈80GPa, and the Poisson ratio falls from≈1to≈0.4. This stiffening indicates that the magnetic order 'locks,' that is, becomes insensitive to lattice strain. This locking might occur because the new stress-induced magnetic order nests the Fermi surface of the Pd sheets. Other frustrated magnets, including candidate spin liquids, may show similarly strong coupling between magnetic and elastic degrees of freedom.

In a dual active bridge converter, the split series inductance configuration with finite magnetizing inductance can provide an additional degree of freedom to optimize the converter's performance. However, this magnetic configuration results in three separate magnetic structures, which increases the volume and footprint. To address this issue, this article proposes a four-winding integrated magnetic structure comprising decoupled primary inductance, secondary inductance, and a transformer capable of independent tuning. The fluxes produced by primary and secondary inductors within the integrated structure consistently oppose in the middle leg of the inductor core, resulting in reduced losses and a smaller volume. A design methodology based on an analytical model has also been developed to systematize the design process. A sensitivity analysis is performed using the finite element method to verify the decoupling operation. An 11 kW, 775 V/450 V prototype is implemented, and the integrated magnetic structure is compared with its discrete implementation under steady-state thermal conditions at different ambient temperatures. A volume reduction of 12.1% and magnetic loss reduction of 4.5% is achieved, while the converter efficiency remains higher or comparable to that of the discrete implementation across the entire operating range.

Magnetic characteristic analysis and structure optimization of magnetic wheel of pipeline robot