The strontium ferrite crystal is like a multi-story building where each floor hosts iron atoms. Some floors "look" up, others down, and their magnetic fields partially cancel each other out. But if some of the residents are replaced with aluminum, which doesn't play the magnetic game, the balance of forces shifts.

Aluminum, as the scientists found, prefers to settle on the "upper" floors, where its presence weakens the coupling with the "lower" floors. As a result, the whole building becomes worse at holding its magnetization when heated: the temperature at which the magnetic floors lose their order creeps downward. However, there's a plus side: to flip all the floors at once, you now need a much larger external field. For a composition with 2.4 aluminum atoms per formula unit, this field reaches 1.2 tesla — almost as strong as the strongest permanent magnets.

This behavior is reminiscent of a tightrope walker who eliminates unnecessary movements to avoid falling. The magnet becomes less "flexible," but much more resistant to external influences. This property is useful for devices where stability of magnetization is important, such as in certain types of memory or high-frequency devices.