Ordering in pyrochlore compounds due to Dzyaloshinsky-Moriya interactions: The case of Cu4O3

Abstract

We investigate the effects of Dzyaloshinsky-Moriya interactions (DMI) on the magnetic properties of the pyrochlore antiferromagnet. The relevance of this interaction for such a system is shown and we describe how to take it into account in accordance with the symmetries of the pyrochlore lattice. A phase transition from a high temperature paramagnetic phase to a low temperature long range ordered state takes place as soon as DMI are present. We describe the different magnetic structures obtained depending on the geometry of the DMI and special attention is given to the compound Cu4O3 for which a possible explanation of the experimentally observed ordering is given.