Researchers from the University of Leeds and the Jožef Stefan Institute have presented new metal-organic structures for magnetic data storage with minimal energy input. In a study published in the prestigious journal Advanced Materials, they demonstrated a reorientation transition of the magnetic moment under the influence of molecular contacts with ferromagnetic films, resulting from competition between the perpendicular magnetic anisotropy induced by a heavy non-magnetic metal and the in-plane magnetic anisotropy caused by molecules. By changing the thickness of the ferromagnet or selecting the molecular overlay layer (C60 and various phthalocyanines), the transition temperature can be adjusted to around room temperature. Near the transition temperature, the direction of magnetization can be easily switched with a small energy input, either by electric current or optically, with a femtosecond laser pulse. The results indicate applications in heat-assisted magnetic recording technologies. Research into ultra-fast switching with short optical pulses was conducted by young researcher Jaka Strohsack and Assoc. Prof. Tomaž Mertelj from the Complex Materials Department at the Jožef Stefan Institute. |
Asst. Prof. Matjaž Gomilšek from the Condensed Matter Physics Department at the Jožef Stefan Institute and the Faculty of Mathematics and Physics, University of Ljubljana has recently published a paper in Physical Review Letters, together with co-authors from the UK, Switzerland, Norway, Germany, Canada, and Japan. In the paper, they revealed a previously overlooked, “hidden” role of local chiral anisotropy in centrosymmetric topological magnets. Specifically, they found that local chiral anisotropy helps stabilize skyrmions and meron–antimeron pairs (different kinds of topological spin textures) in Gd2PdSi3, despite the material’s inversion symmetry, which precludes any global chirality. In their study, they combined atomistic simulations of magnetic ordering with measurements of polarized resonant X-ray scattering on Gd2PdSi3 at electron accelerators Diamond in the UK and PETRA III, DESY in Germany. The discovery represents an important step towards understanding centrosymmetric topological magnets, and greatly expands the possibilities for stabilizing topological spin textures in highly symmetrical materials. |
Researchers from the University of Ljubljana and the Jožef Stefan Institute, Simon Čopar and Uroš Tkalec, in collaboration with researchers from American universities, reported on the spin ordering of topological defects in a confined nematic liquid crystal that forms under a thin layer of water. Shear forces at the boundary between the liquid crystal and water cause the elastic dipoles to align in the direction of the surface movements and thus store information about external stimuli. This results in ordered domain structures in the nematic, similar to those found in systems with polar order, such as ferromagnets, active matter and metamaterials. This is the first application of a conventional liquid crystal in which the director field is controlled by mechanical motion at an open interface and the defect configurations are read using polarization microscopy. The research, which promises new possibilities for the detection of dynamics in microfluidic environments, was published in Nature Physics. Finally, the article is accompanied by a commentary in the News & Views section. |
In a recent paper in Advanced Materials, Peter Medle Rupnik, Nerea Sebastian and Alenka Mertelj from the Department of Complex Matter and Darja Lisjak from the Material Synthesis Department, in collaboration with researchers from Otto-von-Guericke University, Technical University Braunschweig and Merck Electronics KGaA, have demonstrated an example of a liquid that uniquely exhibits both ferroelectric and ferromagnetic ordering. The breakthrough focuses on a nanostructured liquid crystalline hybrid, composed of ferrimagnetic barium hexaferrite nanoparticles suspended in a ferroelectric nematic host, where director-mediated interactions drive the self-assembly of nanoplatelets in an intricate network. This system shows magnetically driven electric and nonlinear optical responses, alongside electrically driven magnetic responses. This achievement marks significant progress toward the development of multiresponsive multiferroic liquids, with promising potential for advanced applications in energy harvesting, nonlinear optics, and next-generation sensors. |
