Lanthanide contraction and magnetism in the heavy rare earth elements

I. D. Hughes, M. Däne, A. Ernst, W. Hergert, M. Lüders, J. Poulter, J. B. Staunton, A. Svane, Z. Szotek & W. M. Temmerman

Nature 446, 650-653 (5 April 2007)

The elemental late rare earths show very different magnetic structures, despite all exhibiting a hcp lattice. Using the electronic structure of
Gadolinium (a prototype for all heavy rare earths) we show that the magnetic structure is determined by the lattice parameters. We calculate the magnetic phase diagram as functions of the lattice parameters and can show that this picture correctly predicts the magnetic structure of all other heavy rare earths. This shows that the lanthanide contraction is responsible for the magnetic order.