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 InLight study: insights into chemical processes using light
05.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Physics, photosynthesis and solar cells
01.12.2016 | University of California - Riverside

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>