Long-range magnetic interaction and frustration in double perovskites Sr₂NiIrO₆ and Sr₂ZnIrO₆.

ABSTRACT: One often counts the nearest neighbouring (NN) exchange interactions for understanding of a magnetic insulator. Here we present first-principles calculations for the newly synthesized double perovskites Sr2NiIrO6 and Sr2ZnIrO6, and we find that the 2NN Ir-Ir antiferromagnetic coupling is even stronger than the 1NN Ni-Ir ferromagnetic one. Thus, the leading antiferromagnetic interactions in the fcc Ir sublattice give rise to a magnetic frustration. Sr2NiIrO6 and Sr2ZnIrO6 hence appear very similarly as a distorted low-temperature antiferromagnet (probably, of type III). This work highlights the long-range magnetic interactions of the delocalized 5d electrons, and it also addresses why the spin-orbit coupling is ineffective here.

SUBMITTER: Ou X 

PROVIDER: S-EPMC4269887 | biostudies-other | 2014

REPOSITORIES: biostudies-other