Antiferromagnetic elements or substances in magnetic assembly components

Antiferromagnetic elements or substances in magnetic assembly components? Below the Neel temperature, the magnetic moments of adjacent atoms in a substance are spontaneously aligned antiparallel and the magnetism exhibited when the combined magnetic moment is zero. In a substance with antiferromagnetism, the magnetic moments of adjacent atoms are equal in size and opposite in direction, so the magnetization is zero, showing weak magnetism.

The value of magnetic susceptibility is similar to that of paramagnetic substances, but it increases with the increase of temperature; above the Neel temperature, the magnetic susceptibility decreases with the increase of temperature, which behaves like paramagnetism.

Metal elements Cr and Mn are antiferromagnetic substances, and some rare earth elements are antiferromagnetic in a certain range of low temperature.

Many antiferromagnetic alloys contain Cr and Mn, and most of them are ordered compounds containing these elements, such as MnAu, CrSb, Mn2As, NiMn, etc. The other is Fe, Co, Ni, Mn oxides, sulfides or halides, such as MnO, FeO, CoO, NiO, MnS, α-Fe2O3, FeS, FeCl2, MnF2, etc.

Disordered alloys are also antiferromagnetic, such as manganese-rich Mn-Cu and Mn-Au alloys; disordered MnCr alloys, when antiferromagnetic transition occurs, not only the magnetic susceptibility changes, but also other physical properties ( Such as expansion coefficient, etc.) also changed. Using this property it is possible to make non-magnetic (no ferromagnetic) low-expansion alloys.