The mystery of the material 'freezes' when heated

In the past, if we cooled magnetic materials to the right temperature, the atom's rotations would "freeze" and lock in place into a static pattern.

A neodymium magnet toy.

Now, however, physicists have accidentally discovered the opposite when they partially heat up the natural magnetic element neodymium.

"The behavior of the magnets in neodymium that we observed is really the opposite of what would normally happen," said Alexander Khajetorians, a physicist at Radboud University in the Netherlands. "This is quite unrealistic, like liquid water becoming a solid rock as it heats up."

This occurs in some materials, such as alloys of copper and iron, where the rotations of the atoms are quite random. This state is called spin glass.

To test this, physicist Benjamin Verlhac of Radboud University and a team of scientists raised the temperature of neodymium from -268 degrees Celsius to -265 degrees Celsius. As a result, a true freezing state occurred. out, with the same form as when we cool another rotating glass system.

Notably, when the scientists tried to cool the neodymium again, the atomic spins fell into disarray once again.

The strange phenomenon occurs when neodymium material is heated, with the same appearance as when "freezing" other magnetic materials.

It remains unclear why this happens, as it is rare for a natural material to behave in a way that is in stark contrast to all other materials of its kind.

Scientists believe it may be related to a physical phenomenon, known as "Geometrical frustration" - which refers to atoms' tendency to stick to unusual positions. It often occurs when the material cannot achieve an orderly pattern, resulting in a disordered ground state.

The researchers also surmise that it is possible that neodymium has certain correlations in its states that depend on temperature. Accordingly, increasing or decreasing the temperature will weaken the bond, causing the disorder mentioned above.

The researchers also note that this has implications far beyond physics, as it could help humanity find new orderings behind every substance. "If we could model the way these materials behave, it would be possible to extrapolate the behavior of many other materials," explains physicist Alexander Khajetorians.