Credit: SciTechDaily.comA team at HZB has examined a brand-new, easy technique at BESSY II that can be utilized to create steady radial magnetic vortices in magnetic thin films.In some materials, spins form complex magnetic structures within the nanometre and micrometer scale in which the magnetization direction twists and curls along particular instructions. Examples of such structures are magnetic bubbles, skyrmions, and magnetic vortices.Spintronics aims to make use of such small magnetic structures to save information or carry out logic operations with extremely low power consumption, compared to todays dominant microelectronic parts. The generation and stabilization of many of these magnetic textures is limited to a couple of products and possible under really particular conditions (temperature level, magnetic field …).” We use the magnetic field created by the superconducting structures to imprint particular magnetic domains on the ferromagnets put on them, and the surface defects to stabilize them.
Researchers have developed a method to create and support complicated spin textures, like radial vortices, using superconducting structures and surface problems. This improvement might substantially affect spintronics by enabling the use of numerous ferromagnetic products and boosting information storage and logic operations with lower power usage. Credit: SciTechDaily.comA team at HZB has actually examined a brand-new, basic technique at BESSY II that can be used to develop steady radial magnetic vortices in magnetic thin films.In some products, spins kind complex magnetic structures within the nanometre and micrometer scale in which the magnetization instructions twists and curls along specific directions. Examples of such structures are magnetic bubbles, skyrmions, and magnetic vortices.Spintronics aims to make usage of such small magnetic structures to perform or keep data logic operations with extremely low power intake, compared to todays dominant microelectronic components. The generation and stabilization of most of these magnetic textures is limited to a couple of products and achievable under extremely specific conditions (temperature level, magnetic field …). A New ApproachAn worldwide collaboration led by HZB physicist Dr Sergio Valencia has actually now investigated a brand-new technique that can be used to develop and support complex spin textures, such as radial vortices, in a range of substances. In a radial vortex, the magnetization points towards or far from the center of the structure. This kind of magnetic configuration is typically highly unstable. Within this unique method, radial vortices are developed with the help of superconducting structures while their stabilization is achieved by the existence of surface area defects.The team led by Sergio Valencia analyzed the samples with photoemission electron microscopy utilizing XMCD at BESSY II. The images show the radially aligned spin textures in a round and a square sample including a ferromagnetic material on a superconducting YBCO island. The white arrow reveals the incident X-ray beam. Credit: © HZBSuperconducting YBCO-IslandsSamples include micrometer-sized islands made from the high-temperature superconductor YBCO on which a ferromagnetic compound is transferred. On cooling the sample listed below 92 Kelvin (-181 ° C), YBCO enters the superconducting state. In this state, an external electromagnetic field is applied and instantly eliminated. This procedure permits the penetration and pinning of magnetic flux quanta, which in turn develops a magnetic roaming field. It is this roaming field that produces brand-new magnetic microstructures in the overlying ferromagnetic layer: spins emanate radially from the structure center, as in a radial vortex.The Role of DefectsAs the temperature is increased, YBCO transits from the superconducting to a normal state. So the stray field developed by YBCO islands vanishes, therefore ought to the magnetic radial vortex. HZB researchers and collaborators have actually observed that the presence of surface area flaws prevents this to happen: the radial vortices partly keep the imprinted state, even when approaching space temperature.” We utilize the magnetic field produced by the superconducting structures to inscribe specific magnetic domains on the ferromagnets put on them, and the surface area defects to stabilize them. The magnetic structures are similar to that of a skyrmion and are intriguing for spintronic applications,” explains Valencia.Geometry MattersSmaller imprinted vortices had to do with 2 micrometers in size, about ten times the size of normal skyrmions. The group studied samples with square and circular geometries and found that circular geometries increased the stability of imprinted magnetic radial vortices.” This is a novel method to develop and stabilize such structures and it can be used in a variety of ferromagnetic products. These are great brand-new prospects for the further development of superconducting spintronics,” says Valencia.Reference: “Size-Dependence and High Temperature Stability of Radial Vortex Magnetic Textures Imprinted by Superconductor Stray Fields” by David Sanchez-Manzano, Gloria Orfila, Anke Sander, Lourdes Marcano, Fernando Gallego, Mohamad-Assaad Mawass, Francesco Grilli, Ashima Arora, Andrea Peralta, Fabian A. Cuellar, Jose A. Fernandez-Roldan, Nicolas Reyren, Florian Kronast, Carlos Leon, Alberto Rivera-Calzada, Javier E. Villegas, Jacobo Santamaria and Sergio Valencia, 2 April 2024, ACS Applied Materials & & Interfaces.DOI: 10.1021/ acsami.3 c17671.
