Superexchange

From Wikipedia, the free encyclopedia

Superexchange (or Kramers-Anderson superexchange) is the strong antiferromagnetic coupling between two next-to-nearest neighbor positive ions through a non-magnetic anion. It is caused as a result of the electrons' having come from the same donor atom and coupled with the receiving ions' spins.

It was proposed by Hendrik Kramers in 1934 when he noticed in crystals like MnO, there are Mn atoms that manage to interact with one another despite having nonmagnetic oxygen atoms between them. Phillip Anderson later refined Kramers' model in 1950.

[edit] References

• P.W. Anderson, Phys. Rev. 79, 350 - 356 (1950)
• [1]
• [2]
• H. A. Kramers, Physica 1, 182 (1934)