Roman Morgunov from the Institute of Problems of Chemical Physics at the Russian Academy of Sciences and his colleagues have now developed a simple additive-based method for ensuring the stability of permanent magnets over time. They have developed methods to counter the spontaneous loss of magnetization, based on their understanding of the underlying physical phenomenon.
The simple additive-based method ensures the stability of permanent magnets over time, with no loss to their main magnetic characteristics.
For physicists, engineers and designers the loss of magnetism in permanent magnets can be a real concern. The response in 1983 was the Japanese company Sumitomo creating the strongest available magnet, one offering ten times more magnetic energy than previous versions.
The Sumitomo magnets are a combination of materials including rare-earth metal and so-called transition metals, and are accordingly referred to as RE-TM-B magnets. The Russian team has now been pushing the boundaries of magnet design, with their study paper published in EPJ Plus.
To design magnets that retain their magnetic stability, the authors altered the chemical composition of a RE-TM-B magnet, Their method consists of inserting small amounts of Samarium atoms at random places within the crystalline sub-lattice of the magnet’s rare-earth component. They observed a multi-fold increase in the magnet’s stability over time with as little as 1% Samarium. The advantage of using such low quantity of additives to stabilize the magnet is that it does not alter the magnetic properties.
The authors believe this result is linked to Samarium’s symmetry. It differs from the crystalline structure of Dysprosium atoms, which enter the composition of the magnet’s rare-earth component. As a result, spontaneous magnetization no longer takes place. This is because the potential barriers separating the magnetization states of different energies are enhanced by the disrupted symmetry.
Further developments of this research will most likely focus on identifying the discrete magnetization jumps – elementary events that initiate the reversible magnetization, leading to a loss in stability.
It will be of great use to have more high power magnets with greater reliability. While magnetism loss isn’t a great far reaching problem, it occurs frequently enough to keep engineers and designers on edge in opting for better magnetism designs. If the Russian team is right and the rare earth level of magnetism can be utterly reliable like current scale manufactured ones, devices will get lighter, more powerful and use less energy.
Good work by the Russian team. Lets hope some folks try replication and it goes well so that industry gets a good look. Perhaps this will lead to better devices for consumers.