Question

Why do ferrimagnetic substances show better magnetism than antiferromagnetic substances?

Answer 1

Hint: Spontaneous magnetization remains in ferrimagnetic materials as the opposing dipole moments are unequal. Spontaneous magnetization is zero in antiferromagnetic materials as the opposing dipole moments are equal and nullify each other.

Complete step by step solution:
Ferrimagnetic substance
-Domains in the ferrimagnetic substances have permanent non-zero dipole moments but are aligned in parallel and antiparallel directions.
-Domains having permanent dipole moments which are aligned in opposite directions do not have the same magnitude of dipole moment. Hence, they do not cancel each other’s dipole moment completely. Ferrimagnetic substances have net dipole moment in absence of magnetic field.
-They have residual magnetic dipole moments and hence are weakly attracted to magnetic fields.
Antiferromagnetic substance
-Domains in the antiferromagnetic substances have permanent non-zero dipole moments but are aligned in parallel and antiparallel directions.
-Domains having permanent dipole moments which are aligned in opposite directions and have the same magnitude of dipole moment. Hence, they cancel each other’s dipole moment completely. antiferromagnetic substances have zero dipole moment in absence of magnetic field.
-They have zero magnetic dipole moments and hence are not attracted to magnetic fields.
Hence, ferrimagnetic substances show better magnetism than antiferromagnetic substances as they have a non-zero net magnetic dipole moment.

Note: Example of Ferrimagnetic substances are $F{{e}_{3}}{{O}_{4}}$ (magnetite) and ferrites like $MgF{{e}_{2}}{{O}_{4}}$ and \[ZnF{{e}_{2}}{{O}_{4}}\]. Examples of Antiferromagnetic substances include hematite, metals such as chromium, alloys such as $FeMn$ (iron manganese), and oxides such as $NiO$ (nickel oxide).