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How does antiferromagnetism cancel a material’s overall magnetism?

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Learn about magnetic fields and the levels of particles, atoms, crystals, and domains — magnet Magnetic fields and the levels of magnetism of particles, atoms, crystals, and domains.

In antiferromagnetic materials, the overall magnetism is canceled because of the specific way atomic dipoles are ordered. Unlike ferromagnets, where dipoles align in parallel, antiferromagnets experience exchange interactions that cause adjacent atomic dipoles to align in an antiparallel manner.12

This ordering requires at least two sets of dipoles pointing in opposite directions. When these sets contain an equal number of dipoles of the same size, the magnetic moments pointing in one direction are perfectly balanced by those pointing in the opposite direction. Consequently, there is no net spontaneous magnetization on a macroscopic scale.12

This state occurs below a characteristic transition temperature known as the Néel temperature. Above this temperature, the material loses this long-range antiparallel order and behaves as a paramagnet. The specific alignment is determined by the exchange interaction between ions, which is influenced by the length of the covalent bond and the bonding angles within the crystal structure.12