For the first time, scientists have observed ferromagnetism in an atomic gas

For the first time, MIT scientists have observed ferromagnetism in an atomic gas, addressing the decades-old question of whether gases could show properties similar to a magnet made of iron or nickel ("Itinerant Ferromagnetism in a Fermi Gas of Ultracold Atoms").
Specifically, the team observed the ferromagnetic behavior in a gas of lithium atoms cooled to 150 billionth of 1 Kelvin above absolute zero (-273 degrees C or -459 degrees F). Team members used the lithium-6 isotope, which consists of three protons, three neutrons and three electrons. Since the number of constituents is odd, lithium-6 is a fermion — a class of exotic particles that have a half-integral spin — and has properties similar to an electron. Therefore, lithium atoms can be used to simulate the behavior of electrons.

Why it matters

For decades, scientists have debated whether it is in principle possible for a gas or liquid of fermions, which are not in a periodic crystal, to become ferromagnetic.

The MIT research appears to provide a compelling affirmative answer to this question.