New Form of Magnetic Order Discovered in Element Neodymium

A material's magnetism may be used within a number of different areas. With the development of greener technology in society, the need of new and improved magnetic materials is expected to become even greater. Researchers from Uppsala University now present new discoveries involving the element neodymium. Neodymium appears to have a hitherto unknown form of magnetic order, built of a mixture of magnetic spirals.

The element neodymium is an important component in strong magnets used in many applications, from mobile phones to wind turbines. Despite these areas of use, magnetism in pure neodymium has perplexed the scientific community in more than a half century. Researchers from Uppsala University and Radboud University in the Netherlands have now shown that neodymium shows a hitherto unknown form of magnetic order, built of a mixture of magnetic spirals.

The different spirals, called spin spirals, easily tangles into each other which means that there is not a well-defined ground state, but the magnetic structure is always changing slowly over time. The behaviour reminds largely of how the atoms in ordinary glass are not frozen in place but are constantly moving. This new type of dynamic magnetic order is therefore called a spin spiral glass. Besides from being able to describe neodymium's magnetism, it is likely that the dynamics exhibited by the spin spiral glass also can be used to describe phenomena in completely different fields, for example artificial intelligence which mimics the behaviour of the brain.

"Neodymium's magnetism has been debated over a long time. Our results also show that the well-studied behaviour of spin glass can occur also in materials which are not disordered, which one previously thought. This means that there are driving forces behind these phenomena which have not yet been fully understood and reasonably there should be many other materials than neodymium that behave like spin spiral glasses," says Anders Bergman, researcher at the Department of Physics and Astronomy at Uppsala University.

"Now we have shown that the phenomenon spin spiral glass itself exists and have a basic understanding of its cause but we want to go further and understand even more about the driving forces behind this phenomenon so we plan to continue studying both neodymium but also other materials which we believe may show similar behaviour," says Diana Iuşan, researcher at the Department of Physics and Astronomy at Uppsala University.

At Uppsala University, the researchers Anders Bergman, Diana Iuşan, Lars Nordström and Olle Eriksson have worked on the study.