When cooled to -272°C, the Fe₄Nb₂O₉ crystal turns into a magnetic pattern where atomic arrows don't line up in a single row but fan out. It's like a crowd frozen in place, but each person looks in their own direction rather than at the back of the neighbor's head. This arrangement of magnetic moments is called non-collinear, and it turns out to be responsible for the material's unusual behavior.

Scientists bombarded the sample with neutrons and tracked the reflected beams. Unlike X-rays, neutrons are sensitive to the magnetic fields of atoms, so the diffraction pattern reveals the directions of the magnetic arrows. It turned out that at 1.5 Kelvin (which is -271.65°C), a noticeable component of the magnetic moment appears along the vertical axis, and the moments themselves form an antiferromagnetic structure — neighboring atoms point in opposite directions, but not strictly opposite, rather at an angle.

This structure explains why Fe₄Nb₂O₉ responds so strongly to a magnetic field by changing its dielectric permittivity. When the field rotates the magnetic arrows, the crystal lattice deforms slightly, and the material's electrical properties change. This phenomenon is called the magnetoelectric effect, and it paves the way for devices where a magnetic field controls electric current without wires.

Now that the exact magnetic pattern is known, engineers can tune crystal growth conditions to enhance the desired effect. Such materials might find their way into magnetic field sensors, non-volatile memory, or elements that convert vibrations into electricity.