Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Computational high-throughput screening finds hard magnets containing less rare earth elements

25.05.2016

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of thorium-manganese crystalline structure.


Left: the crystal structure of thorium manganese (ThMn12) with atoms of neodymium (blue balls) has better magnetic properties than super magnets, though is unstable; right: more stable structure.

The image © Fraunhofer Institute for Mechanics of Materials IWM

“The neodymium-iron-nitrogen compound we used has better magnetic properties than current super magnets made of neodymium, iron, and boron,” explains Georg Krugel, though the material is apparently not yet stable, having only been produced in thin layers up to now.

The goal of the group Materials Modeling’s project was to identify a new permanent magnet that exhibits the same or better magnetic properties, such as strength and directional stability, as well as the required material stability. Differing atoms in the crystal structure were systematically varied across a range of values using the new HTS process.

The researchers initially replaced the neodymium atoms with other rare earth elements such as cerium, which is considerably more economical. They then substituted iron partially by transition metals like cobalt, nickel, and titanium as well as by other elements like silicon. The HTS produced 1,280 variations this way that the researchers analyzed with respect to their properties.

Concentration on material stability, strength, and directional stability of the magnetization

“We concentrated on three properties quite important for applications during our analyses of the variations in materials,” explains Krugel. The researchers first examined the stability of the material, which could be estimated from the energy of formation. The second important aspect is the maximum attainable energy product, which allows the strength of the magnet to be estimated. The energy of anisotropy, which is a measure of the directional stability of the magnetization, is also very important for the intended application. The researchers were able to identify twelve especially promising candidates from among the 1280 variations this way.

Validation with the help of existing experimental magnetic materials

The pivotal question of course is whether the calculated properties of the variations in materials created in the computer correspond to reality. The researchers therefore additionally validated them against existing permanent magnets. The results confirmed the predictive power of the model for the magnetic properties of the HTS candidates.

General trends

Besides identifying promising approaches in materials for new permanent magnets, the researchers were able to ascertain important general trends through their work. “It was evident that cerium and neodymium are better suited on the whole than samarium," according to Krugel. Cerium in particular exhibited extremely high anistropy. Among the transition metals, the researchers were able to increase the predictability of titanium’s suitability especially.

“While transition metals reduce the strength of the magnet, they increase its directional stability considerably as well," Krugel summarizes. Valid predictions can also now be made for atoms additionally incorporated into the crystal lattice. Nitrogen and carbon are better suited than boron utlilized in current supermagnets.

New kinds of magnets might be able to be made experimentally based on the predictions of the new HTS approach. Computer-aided predictions offer an avenue for industry to identify and improve materials required to have specific properties.

Publication:
Körner, W. et al. Theoretical screening of intermetallic ThMn12-type phases for new hard-magnetic compounds with low rare earth content. Sci. Rep. 6, 24686; doi: 10.1038/srep24686 (2016).

Weitere Informationen:

http://www.nature.com/articles/srep24686 - link to publication
http://www.en.iwm.fraunhofer.de/business-units/materials-design/materials-modeli... - link to group Materials Modeling

Katharina Hien | Fraunhofer-Institut für Werkstoffmechanik IWM

Further reports about: Fraunhofer-Institut HTS IWM magnetization neodymium rare earth elements

More articles from Materials Sciences:

nachricht Melting solid below the freezing point
23.01.2017 | Carnegie Institution for Science

nachricht An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>