Phys.org October 30, 2024 The rare earth RMn6Sn6 (R = rare earth) family magnetic kagome systems, where their kagome flat bands are calculated to be near the Fermi level in the paramagnetic phase have been reported. While partially filling a kagome flat band is predicted to give rise to a Stoner-type ferromagnetism, experimental visualization of the magnetic splitting across the ordering temperature has not been reported for any of these systems leaving the nature of magnetism in kagome magnets an open question. An international team of researchers (USA – Rice University, Brookhaven National Lab, Los Alamos National Laboratory, Israel, Czech Republic) probed […]
Tag Archives: Magnetism
Doughnut-shaped region found inside Earth’s core deepens understanding of planet’s magnetic field
Phys.org August 30, 2024 Thermochemical inhomogeneities in the Earth’s outer core that enhance our understanding of the geodynamo have been elusive. Seismic constraints on such inhomogeneities would provide clues on the amount and distribution of light elements in the core apart from iron and nickel. Researchers in Australia found evidence for a low-velocity volume within the outer core via the global coda correlation wavefield. Several key correlogram features with a unique sensitivity to the liquid core showed variations with wave paths remarkably slower in the equatorial than polar planes constrained a torus structure at low latitudes with lower velocity than […]
Controlling magnetism with polarized light: Non-thermal pathway uses inverse Faraday effect
Phys.org July 5, 2024 Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism on timescales as short as the excitation pulse itself. As the IFE scales with the spin-orbit coupling strength of the involved electronic states, photo-exciting the strongly spin-orbit coupled core-level electrons in magnetic materials appears as an appealing method to transiently generate large opto-magnetic moments. An international team of researchers (Germany, France, Canada, Italy, Spain, Slovenia, Sweden, UK) investigated this scenario in a ferrimagnetic GdFeCo alloy by using intense and circularly polarized […]
Scientists create world’s strongest iron-based superconducting magnet using AI
Phys.org June 7, 2024 Iron-based high-temperature (high-Tc) superconductors have good potential to serve as materials in next-generation superstrength quasipermanent magnets owing to their distinctive topological and superconducting properties. However, their unconventional high-Tc superconductivity paradoxically associates with anisotropic pairing and short coherence lengths, causing challenges by inhibiting supercurrent transport at grain boundaries in polycrystalline materials. An international team of researchers (Japan, UK) manipulated intricate polycrystalline microstructures resulting in a bulk Ba0.6K0.4Fe2As2 permanent magnet with a magnetic field that was 2.7 times stronger than previously reported. They demonstrated magnetic field stability for a practical 1.5 T permanent magnet, which is a vital aspect […]
The Earth’s changing, irregular magnetic field is causing headaches for polar navigation
Phys.org May 27, 2024 Researchers at the University of Michigan statistically studied large magnetic field vector residuals between Swarm observations and the 13th generation International Geomagnetic Reference Field (IGRF-13) model under quiet to moderate geomagnetic conditions. All large residuals appeared in the high latitude auroral zone region peaking around 70° magnetic latitude (MLAT) with a secondary occurrence peak just below 80° MLAT. However, the two hemispheres showed clear asymmetries in the magnetic longitude and magnetic local time distribution where both hemispheres showed high concentration of large residuals around the geographic poles. Since polar satellite’s orbits give rise to highly biased […]
Stable magnetic bundles achieved at room temperature and zero magnetic field
Phys.org May 10, 2024 Through a combination of pulsed currents and reversed magnetic fields, researchers in China experimentally achieved skyrmion bundles with different integer Q values in the chiral magnet Co8Zn10Mn2. They demonstrated the field-driven annihilation of high-Q bundles and presented a phase diagram as a function of temperature and field. Their findings were corroborated by micromagnetic simulations… read more. Open Access TECHNICAL ARTICLE
The spontaneous emergence of 1D superconducting stripes at a 2D interface in an oxide heterostructure
Phys.org April 8, 2024 Magnetism can cause a modulation of superconducting pairing in real space in both copper-based and iron-based materials. Researchers in China reported on the discovery of a spatially varying superconducting state residing at the interface between KTaO3 and ferromagnetic EuO. Electrical transport measurements revealed different values of the critical temperature and magnetic field at which the superconductivity breaks down when current was applied along the two orthogonal in-plane directions. This anisotropy occurred in low-carrier-density samples that were characterized by strong coupling between the Ta 5d and Eu 4f electrons, whereas in high-carrier-density samples, the coupling was weakened, […]
Magnetic avalanche triggered by quantum effects: ‘Barkhausen noise’ detected for first time
Phys.org March 28, 2024 Most macroscopic magnetic phenomena (including magnetic hysteresis) are typically understood classically. An international team of researchers (USA – Caltech, University of Colorado, University of Chicago, University of Tennessee, Canada, Japan, UK) examined the dynamics of a uniaxial rare-earth ferromagnet deep within the quantum regime, so that domain wall motion, and the associated hysteresis, was initiated by quantum nucleation, which then grew into large-scale domain wall motion, that was observable as an unusual form of Barkhausen noise. They found that the “quantum Barkhausen noise” exhibited two distinct mechanisms for domain wall movement, each of which was quantum-mechanical, […]
Nano weaving creates ‘Chinese knot’ magnetism for powerful microwave shielding
Nanowerk February 7, 2024 Harnessing tailored nanoscale magnetic materials like metal-organic frameworks for advanced applications has faced two key challenges – reliably constructing these frameworks with specific and programmable architectural arrangements and effectively characterizing these nanostructures. Researchers in China strategically dispersed magnetic Co nanoparticles into a meticulously layered nanoporous framework with the bottom and upper nanopores exhibiting a staggered arrangement. The staggered nanoporous structure intricately shapes the magnetic flux lines into a Chinese knot shape, significantly altering its magnetic characteristics. Such a transformation remarkably enhances the material’s efficacy in absorbing electromagnetic waves, covering the Ku band even at a minimal […]
Strange New Kind of Magnetism Found Lurking In Material Just Six Atoms Thick
Science Alert February 4, 2024 The existence of alternate mechanisms for magnetism that could naturally facilitate electrical control has been discussed theoretically but an experimental demonstration has not been done. An international team of researchers (Switzerland, Spain, US -University of Tennessee, Japan) investigated MoSe2/WS2 van der Waals heterostructures in the vicinity of Mott insulator states of electrons forming a frustrated triangular lattice and observed direct evidence of magnetic correlations originating from a kinetic mechanism. By directly measuring electronic magnetization they found that when the Mott state was electron-doped, the system exhibited ferromagnetic correlations in agreement with the Nagaoka mechanism… read […]