Question

Is ${\text{MgF}}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{4}}}$ ferrimagnetic?

Answer 1

Hint: We know that ferromagnetism is a type of permanent magnetism which occurs in solids in which the magnetic fields associated with individual atoms align themselves spontaneously, some parallel or in the same direction and some antiparallel or in opposite directions.

Complete answer:
${\text{(MgF}}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{4}}})$ is ferrimagnetic. But when it is heated, it loses its ferrimagnetism and becomes paramagnetic. As temperature is raised, randomization of spin takes place and the alignment and order between the dipoles gets destroyed. Hence, it loses its intrinsic magnetic moment and shows induced magnetism. Note that the magnetic behavior of single crystals of ferrimagnetic materials are attributed to the parallel alignment/ The diluting effect of the atoms in the antiparallel alignment keeps the magnetic strength of ferrimagnetic materials less than that of purely ferromagnetic solids. Ferrimagnetism mainly occurs in magnetic oxides called ferrites. When ferrimagnetic substances are heated to a certain temperature known as the Curie temperature, they become paramagnetic in nature. This generally happens because of the realignment of the electron spins or their magnetic moments which will be now oriented in one particular direction.
Therefore, ${\text{MgF}}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{4}}}$ is ferrimagnetic.

Note:
Basically, there are six types of magnetization: diamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, ferrimagnetism and superparamagentism. Diamagnetic materials have a tendency to move from the stronger part to the weaker part of the external magnetic field. These substances are repelled by a magnet. Paramagnetic materials are weakly magnetized in the presence of an external magnetic field and they tend to move from a weaker region to a strong magnetic field.