I guess ferrimagnetic systems can be fully compensated just at a certain temperature where the different atoms have exactly the same moment. whereas in antiferromagnets each magnetic moment within the lattice is always the same in magnitude as they belong to identical atoms and maintain this behaviour all the way up to their Curie temperture.

Marco Asa So what you are saying is two different atoms with equal but opposite moments cannont make an antiferromagnet?

Magnetic properties in AFM an compensated ferrimagnet might be similar in terms of net magnetic moment, damping and such, but other properties like dichroism and spin-dependent transport would be in general different. So it still make a lot of sense to distinguish the two and give proper names. Again, I am not aware of a fully compensated ferrimagnet in a wide temperature range, but i'm outside of this research by several years.

Marco Asa thanks a lot.