12-Aug-2022 - Max-Planck-Institut für Eisenforschung

Better magnets for green energy

Researchers use multicomponent alloys to make strong and ductile soft magnetic materials

Soft magnetic materials (SMMs) applied in electric engines transform energy from sustainable resources into electricity. Conventional SMMs, which are currently used in industry, are prone to damage under severe mechanical loads. Researchers from the Max-Planck-Institut für Eisenforschung (MPIE), the Technical University of Darmstadt and the Central South University, China, have developed a new design strategy that increases the lifetime of SMMs and paves the way for advanced applications like high-speed motors. They published their recent findings in the journal Nature.

Introducing nanoparticles for increase in strength and ductility

“The current problem we are facing in conventional soft magnetic materials is the trade-off between being magnetic soft on the one hand, and mechanically strong on the other hand”, explains Liuliu Han, doctoral researcher at the MPIE and first author of the publication. Higher strength in materials is usually achieved through the implementation of microstructural features such as precipitations and defects. According to the state of the art, introducing these nanoparticles into soft magnetic materials will pin the movement of the domain walls thus decrease the magnetising force. The scientists discovered that the size of the nanoparticles plays a crucial role for both, the mechanical strength and ductility of the magnets and their magnetism. “Till now it was assumed that smaller nanoparticles interact less with the domain walls and are therefore preferred. However, quite the opposite is true. We implemented particles that are slightly below the domain wall width. This coarsening means a smaller specific surface area and reduced the internal stress level so that the magnetic properties were not affected”, says Han.

Multicomponent alloy system for advanced soft magnets

The researcher team realized this design idea in a multicomponent alloy system, derived from the high entropy alloy concept, containing iron, nickel, cobalt, tantalum and aluminium with multifunctional properties, which is not common for conventional soft magnets targeting soft magnetic properties mainly. In addition, materials based on the new alloy system are easier to manufacture and have a higher lifetime than the conventional magnetic materials. “With the help of computational calculations and machine learning, we are now trying to find ways to reduce the cost of the proposed alloy by reducing the amount of the containing expensive elements, such as cobalt, and by finding substitutes with similar properties”, says Dr. Fernando Maccari, postdoctoral researcher in the Functional Materials group at TU Darmstadt and second author of the publication. Magnetic properties were investigated at TU Darmstadt, whereas the design of the composition and the characterization of the alloy was done at the MPIE.

The alloy composition used here serves as a model system for multicomponent alloys. The concept of using multicomponent alloys is not limited to soft magnetic materials, but is applicable for advanced alloys with new and unusual combinations of functional and mechanical properties.

Facts, background information, dossiers
More about MPI für Eisenforschung
  • News

    Ice on gold

    How to analyse ice down to its atomic scale? And how to analyse objects embedded in ice without melting it? An international team of material scientists mainly from the Max-Planck-Institut für Eisenforschung (MPIE) found a way to analyse micron-thick layers of ice by atom probe tomography ( ... more

    How to design more reliable nano- and micro-electro-mechanical systems

    Mobile phones, data storage for laptops, solar cells, power electronics for renewable energy, or sensors in cars are applications where silicon is the first-choice material despite that its mechanical behaviour at elevated temperature is not yet fully understood. To design efficient and rel ... more

    Material Scientist wins European Science Slam Championship

    Aniruddha Dutta, doctoral student at the Max-Planck-Institut für Eisenforschung (MPIE) in Düsseldorf and acting German science slam champion 2018/19, has won the European Science Slam Championship 2019/20 against his competitors from Austria, Switzerland, Sweden, Slovakia, Slovenia, the Cze ... more

  • Research Institutes

    Max-Planck-Institut für Eisenforschung

    At the Max-Planck Institut für Eisenforschung GmbH (MPIE), research is carried out on iron, steel and related materials, such as nickel, titanium and intermetallic phase alloys. An essential target of the investigations is an improved understanding of the complex physical processes and chem ... more

More about Max-Planck-Gesellschaft
  • News

    One chemist to keep an eye on

    The American journal “Science news” awards ten young scientists each year as “scientists to watch”. Josep Cornellà, group leader at the Max-Planck-Institut für Kohlenforschung, is now one of them. For about one century the American magazine "Science News" has been reporting on current devel ... more

    More Sustainability with Mechanochemistry

    Flour, coffee or spices: Many people know the principle of a mill from the kitchen. But special mills are also used for research purposes in the laboratories of the Max-Planck-Institut für Kohlenforschung. The scientists are convinced that mechanochemistry can make the chemical industry mor ... more

    Terahertz light from superconducting stripes

    Why do some materials carry electrical currents without any resistance only when cooled to near absolute zero while others do so at comparatively high temperatures? This key question continues to vex scientists studying the phenomenon of superconductivity. Now a team of researchers from And ... more