Phys.org December 11, 2024 The presence of net magnetization limits device scalability and compatibility with phases, such as superconductors and topological insulators. Altermagnetism has been proposed as a solution to these restrictions combined with the antiferromagnetic-like vanishing net magnetization. So far, altermagnetic ordering has been inferred from spatially averaged probes. An international team of researchers (UK, Switzerland, Czech Republic, Germany) demonstrated nanoscale imaging of altermagnetic states from 100-nanometre-scale vortices and domain walls to 10-micrometre-scale single-domain states in manganese telluride. They combined the time-reversal-symmetry-breaking sensitivity of X-ray magnetic circular dichroism with magnetic linear dichroism to achieve maps of the local altermagnetic […]
Tag Archives: Ferromagnets
Making ferromagnets ready for ultra-fast communication and computation technology
Phys.org June 14, 2024 Spin-torque driven critical spin dynamics, such as auto-oscillations, play the central role in many spin-based technologies. An international team of researchers (USA – UC Riverside, Johns Hopkins University, Germany, India, Ukraine) developed the theoretical framework of precessional auto-oscillations for ferromagnets with spin inertia. They discovered and introduced the concept of nutational auto-oscillations and demonstrated that they can become pivotal for future ultrahigh frequency technologies. They showed parallels between spin dynamics in ferrimagnets and inertial ferromagnets and derived an isomorphism that established a foundation for synergistic knowledge transfer between these research fields… read more. TECHNICAL ARTICLE
When injecting pure spin into chiral materials, direction matters
Science Daily May 3, 2024 The chiral induced spin selectivity (CISS) effect is emerging as a design principle for creating next-generation spintronic devices. CISS implies that the spin preference of chiral structures persists upon injection of pure spin currents and can act as a spin analyzer without the need for a ferromagnet. A team of researchers (North Carolina State University, University of Pittsburgh, University of Illinois – Urbana) showed that an anomalous spin current absorption in chiral metal oxides that manifested a colossal anisotropic nonlocal Gilbert damping with a maximum-to-minimum ratio of up to 1000%. A twofold symmetry of the […]
Antiferromagnets are suitable for transporting spin waves over long distances, study finds
Phys.org December 6, 2022 In antiferromagnets, the efficient transport of spin-waves has until now only been observed in the insulating antiferromagnet hematite, where circularly polarized spin-waves diffuse over long distances. An international team of researchers (Germany, France, Norway, China) observed long-distance spin-transport in the antiferromagnetic orthoferrite YFeO3, where a different transport mechanism was enabled by the combined presence of the Dzyaloshinskii-Moriya interaction and externally applied fields. The magnon decay length exceeded hundreds of nanometers, in line with resonance measurements that highlight the low magnetic damping. They observed a strong anisotropy in the magnon decay lengths which they attributed to the […]
Antiferromagnetic hybrids achieve important functionality for spintronic applications
Phys.org August 23, 2033 Previous studies have shown spin injection and detection in antiferromagnet/nonmagnetic metal bilayers; however, spin injection in these systems has been found effective only at cryogenic temperatures. An international team of researchers (USA – UC Riverside, University of Utah, Germany) has demonstrated sizable interfacial spin transport in a hybrid antiferromagnet/ferromagnet system, consisting of Cr2O3 and permalloy, which remains robust up to the room temperature. They examined their experimental data within a spin diffusion model and found evidence for the important role of interfacial magnon pumping in the signal generation. The results bridge spin-orbitronic phenomena of ferromagnetic metals […]
Tiny electrical vortexes bridge gap between ferroelectric and ferromagnetic materials
EurekAlert February 9, 2022 An international team of researchers (UK, Ireland, USA – Argonne National Laboratory) created a thin film of the ferroelectric lead titanate sandwiched between layers of the ferromagnet strontium ruthenate, each about 4 nanometres thick. The structure of the combined layers revealed that the domains in the lead titanate were a complex topological structure of lines of vortexes, spinning alternately in different directions. Almost identical behaviour has also been seen in ferromagnets where it is known to be generated by the Dzyaloshinskii–Moriya interaction (DMi). According to the researchers the difference between ferromagnetism and ferroelectricity becomes less and […]
Energy harvesting technology based on ferromagnetic resonance
Phys.org August 24, 2021 Researchers in Japan demonstrated electrical charging using the electromotive force (EMF) generated in a ferromagnetic metal (FM) film under ferromagnetic resonance (FMR). In the case of Ni80Fe20 films, electrical charge due to the EMF generated under FMR can be accumulated in a capacitor; however, the amount of charge is saturated well below the charging limit of the capacitor. In the case of Co50Fe50, electrical charge generated under FMR can be accumulated in a capacitor and the amount of charge increases linearly with the FMR duration time. The difference between the Ni80Fe20 and Co50Fe50 films is due […]
Exotic property of ‘ambidextrous’ crystals points to new magnetic phenomena
Phys.org August 4, 2021 Researchers in Sweden used symmetry-based analysis and numerical computations to predict the existence of antichiral ferromagnetism—a kind of ferromagnetic ordering when both types of chirality (handedness) exist simultaneously and alternate in space. They predicted a fundamentally different magnetic ordering in tetrahedral ferromagnets. They showed that antichiral ferromagnetism can be observed in a class of crystals in which many minerals are formed naturally by studying magnetic ordering in the structure with tetrahedral crystal symmetry and used micromagnetic analysis to derive the new antichiral ordering. The proposed magnetic ordering might result in a rich family of magnetic phenomena […]
Scientists discover a ‘tunable’ novel quantum state of matter
Nanowerk September 12, 2018 An international team of researchers (China, USA – Boston College, Princeton University, Lawrence Berkeley National Laboratory, Taiwan) arranged atoms on the surface of crystals in many different patterns on ferromagnet to explore the associated phenomena. The electrons hovering above their atoms aligned in a straight line, with two-fold symmetry ignoring the lattice symmetry. When a magnetic field was applied they could turn one line in any direction they chose rotating the line of electrons just by controlling the magnetic field around them. Anisotropy was 100 times more than what theory predicts. The findings open enormous possibilities […]