Page "Magnetism" Paragraph 38

Like ferromagnetism, ferrimagnets retain their magnetization in the absence of a field.

However, like antiferromagnets, neighboring pairs of electron spins like to point in opposite directions.

These two properties are not contradictory, because in the optimal geometrical arrangement, there is more magnetic moment from the sublattice of electrons that point in one direction, than from the sublattice that points in the opposite direction.