superexchange, or kramers–anderson superexchange, is the strong (usually) antiferromagnetic coupling between two next-to-nearest neighbour cations through a non-magnetic anion. in this way, it differs from direct exchange in which there is coupling between nearest neighbor cations not involving an intermediary anion. superexchange is a result of the electrons having come from the same donor atom and being coupled with the receiving ions' spins. if the two next-to-nearest neighbor positive ions are connected at 90 degrees to the bridging non-magnetic anion, then the interaction can be a ferromagnetic interaction.