Scientists from BFU took part in experiment dedicated to research of magnetic phenomena on the atomic level
Researchers from Immanuel Kant Baltic Federal University as a part of international team conducted the unique experiment to study magnetic properties of thin films on the base of metal compounds. In frames of the experiment researchers found out new important effects of formation of spintronic structures, the work of which was based on change of magnetic moments (spins) of electrons. Thus, for example, in multilayered films on the base of cobalt-iron-boron during application of molybdenum layer authors described the effect of perpendicular magnetic anisotropy, which was key for modern spintronic devices. Results of the research are published in journal Vacuum.
Spintronics is one of the most rapidly developing fields of modern nanoelectronics where devices use for work the spin degree of freedom of electrons. With the help of such devices, it's possible to achieve higher density of data recording at high speed of recording, significantly reduce energy consumption, and also create memory cells, that are able to save information even when power is off. For realization of such devices, you need materials with specific magnetic properties. One of them is perpendicular magnetic anisotropy—the ability of thin materials in the form of films to magnetize in the direction, perpendicular to their plane (that is by their very small width). However, to research this phenomenon in thin metal films, that can be used in spintronics, is very difficult due to small scales and interface effects. Existing approaches don't provide the required accuracy, so scientists are looking for effective alternatives.
Researchers from Immanuel Kant Baltic Federal University (Kaliningrad) together with colleagues from Sweden, France and Germany formed multi-layered thin films from various metal compounds and in the real-time mode studied their magnetic properties. The experiment was conducted with the use of specially designed installation: compact vacuum chamber, that was integrated into neutron reflectometer—a device, that gives bundles of neurons (neutral particles) to the studied material. The reflection of neurons from the sample makes it possible to trace magnetic properties of atomic layers with high accuracy. Such system enables to grow multi-layered thin films in-situ and immediately measure their properties.
The chamber for deposition of layers works on the principle of laser deposition: under the influence of laser thin layers of metal compounds are deposited on silicon substrate, forming the structure in millionth parts of millimeter width. After each deposited layer scientists direct on the sample the bundle of neurons, that, interacting with magnetic moments of atoms, are reflected in a specific way. This enables to fix changes in magnetic structure with atomic accuracy.
The experiment with the use of thin layers of cobalt-iron-boron showed that application of molybdenum layer on them caused the emergence of perpendicular magnetic anisotropy. This effect is explained by the influence of heavy atoms of molybdenum on neighboring magnetic atoms that makes them orientate perpendicularly to film's plane. Perpendicular magnetic anisotropy is the key effect for modern spintronic devices, that's why its discovery potentially enables to use studied structures in spintronic devices.
"We can observe how exactly on borders of layers magnetic properties begin to form that are critically important for data storage devices and energy efficient electronics. This becomes possible thanks to the unique international collaboration and use of the advanced installation of neural reflectometry",—comments Petr Shvets, candidate of Physico-mathematical Sciences, head of the Laboratory of Complex Oxides of Immanuel Kant Baltic Federal University.
More information:
doi.org/10.1016/j.vacuum.2025.114521
Provided by Immanuel Kant Baltic Federal University
