Question

Which of the following arrangements shows the schematic alignment of magnetic moments of antiferromagnetic substance?

A.

B.

C.

D.

Answer 1

Hint: Magnetic moment is the quantity that determines the force that the substance can exert on electric current and the torque that magnetic field will exert on magnetic moment. Antiferromagnetic substance has zero net magnetic moment.

Complete step by step solution:
Since we know that antiferromagnetic substances are common as metal and transition compounds. Also antiferromagnetic has zero net magnetic moment because it is arranged in such a way that it cancels all the magnetic moments.
The arrangement of antiferromagnets is that each neighbor is anti-parallel. Since the domains are oppositely oriented and cancel out each other’s magnetic moment.
Considering all facts above if we check the given options:
Option A is aligning in the same direction. Hence this is not correct.
Option B is showing opposite alignment but at two arrows are aligning in the same direction. So this option is not correct.
Option C alignments show that all the middle arrows are pointing towards down. So this option is not correct.
Option D alignments are perfectly anti-parallel, that is they are oppositely aligned to each other and hence canceling each other magnetic moments. So this option is correct.

So, the correct answer is option D.

Additional information:
Antiferromagnetic material or substance is quite the same to ferromagnetic material as there is strong quantum interaction between neighboring atomic molecules.
Magnetic moment is the magnetic strength of a magnet that produces a magnetic field. The strength and direction of magnetic moments depends on magnitude of magnetic moment and also on orientation relative to direction of magnetic field. Magnetic moments can be considered as vectors. Direction of magnetic moment points from the south to north pole of the inside the magnet and vice versa for outside of the magnet. Examples of objects which have magnetic moments are permanent magnets, molecules, elementary particles and so on.

Note: To know which substance is this using a magnetic moment consider the alignment and orientation of the arrows. Main point to remember for an antiferromagnetic substance is that it has zero net magnetic moment so the orientation will be antiparallel so that it cancels all magnetic moments.