Spintronics: A new path to room temperature swirling spin textures

Science  Daily April 17, 2024 In spintronics the generation and stabilization of most of the magnetic textures is restricted to a few materials and achievable under very specific conditions (temperature, magnetic field…). Recently, a new approach has shown potential for the imprint of magnetic radial vortices in soft ferromagnetic compounds making use of the stray field of YBa2Cu3O7-δ superconducting microstructures in ferromagnet/superconductor (FM/SC) hybrids at temperatures below the superconducting transition temperature (TC). Using a new approach an international team of researchers (France, Spain, Germany) explored the lower size limit for the imprint of magnetic radial vortices in square and disc […]

Spintronics research shows material’s magnetic properties can predict how a spin current changes with temperature

Phys.org  April 23, 2024 An international team of researchers (Japan, Australia) examined magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons through the spin-Seebeck effect and neutron scattering measurements. The compound showed a magnetic compensation, where the spin-Seebeck signal reversed above and below K. Unpolarized neutron scattering unveiled two major magnon branches with finite energy gaps which were well explained in the framework of spin-wave theory. Their temperature dependencies and the direction of the precession motion of magnetic moments defined using polarized neutrons explained the reversal at and decay of the spin-Seebeck signals at low temperatures. According to […]

Study hints at new way to improve on spintronics for future tech

Nanowerk  October 13, 2023 An international team of researchers (USA- Ohio State University, Sweden, UK) used a new method involving the reflection of polarized light on thin films of light metal chromium, successfully detected the orbital Hall effect. The orbital polarization was in-plane, transverse to the current direction, and scaled linearly with current density, consistent with the orbital Hall effect. Comparing the thickness-dependent magneto-optical measurements with ab initio calculations, they estimated an orbital diffusion length in Cr of 6.6±0.6nm. The potential application of this discovery in spintronics could lead to improve data storage in the next generation of computer devices […]

Laser light hybrids control giant currents at ultrafast times

Phys.org  April 13, 2023 Spin and valley indices represent the key quantum labels of quasi-particles in a wide class of two-dimensional materials and form the foundational elements of the fields of spintronics and valleytronics. Researchers in Germany have discovered a route to induce and control the flow of spin and valley currents at ultrafast times with specially designed laser pulses, offering a new perspective on the ongoing search for the next generation of information technologies. They showed that femtosecond laser light combining optical frequency circularly polarized pulse and a terahertz (THz) frequency linearly polarized pulse can generate precisely tailored and […]

Single-electron devices could manage heat flow in electronic components

Nanowerk  December 8, 2022 Previous heat engines based on quantum dots have used reservoirs of electrons at different temperatures. An international team of researchers (Japan, Germany) has fabricated a nanoscale ‘heat engine’ that uses a property of spin as the effective working medium. They confined electrons using electric fields generated at surface metal electrodes on a gallium arsenide surface. The device had two interlinked quantum dots and a built-in charge sensor to passively monitor what was going on within the double quantum dot. A third quantum dot was used to control the double quantum dot’s thermal environment. According to the […]

Novel nanowire fabrication technique paves way for next generation spintronics

Nanowerk  November 9, 2022 Eliminating the etching process by directly fabricating nanowires onto the silicon substrate would lead to a marked improvement in the fabrication of spintronic devices. However, when directly fabricated nanowires are subjected to annealing, they tend to transform into droplets as a result of the internal stresses in the wire. Researchers in Japan have developed a new fabrication process to make L10-ordered CoPt nanowires on silicon/silicon dioxide (Si/SiO2) substrates. They coated a Si/SiO2 substrate with a material called a ‘resist’ and subjected it to electron beam lithography and evaporation to create a stencil for the nanowires, deposited […]

One-unit-cell thick semiconductors with room-temperature magnetism

Nanowerk  November 15, 2022 Researchers in China have developed a confined-van der Waals epitaxial approach to synthesizing air-stable semiconducting cobalt ferrite nanosheets with thickness down to one unit cell using a facile chemical vapor deposition process. They demonstrated hard magnetic behavior and magnetic domain evolution by means of vibrating sample magnetometry, magnetic force microscopy and magneto-optical Kerr effect measurements, which showed high Curie temperature above 390 K and strong dimensionality effect. According to the researchers their work provides possibilities for numerous novel applications in computing, sensing and information storage…read more. Open Access TECHNICAL ARTICLE 

Researchers develop a material that mimics how the brain stores information

Nanowerk  November 8, 2022 While a precise modulation of magnetism is achieved when voltage is applied, much more uncontrolled is the spontaneous evolution of magneto-ionic systems upon removing the electric stimuli. An international team of researchers (Spain, Italy, Belgium) has demonstrated a voltage-controllable N ion accumulation effect at the outer surface of CoN films adjacent to a liquid electrolyte, which allows for the control of magneto-ionic properties both during and after voltage pulse actuation (i.e., stimulated, and post-stimulated behavior, respectively). This effect, which takes place when the CoN film thickness is below 50 nm and the voltage pulse frequency is […]

Magnetism or no magnetism? The influence of substrates on electronic interactions

Nanowerk  November 9, 2022 While technological developments of 2D MOFs typically take advantage of substrates for growth, support, and electrical contacts, investigations often ignore substrates and their dramatic influence on electronic properties. Researchers in Australia have shown how substrates alter the correlated magnetic phases in Kagome MOFs using systematic density functional theory and mean-field Hubbard calculations. They demonstrated that MOF-substrate coupling, MOF-substrate charge transfer, strain, and external electric fields are key variables, activating and deactivating magnetic phases in these materials. They used the Kagome-arranged 9,10-dicyanoanthracene molecules coordinated with copper atoms as an example. According to the researchers their findings can […]

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 […]