Tuning the antiferromagnetic helical pitch length and nanoscale domain size in Fe3PO4O3 by magnetic dilution

We have investigated the effect of magnetic dilution (substituting Ga for Fe) on the partially ordered helical antiferromagnetic ground state of Fe3PO4O3.  The helical state in this compound is known to form in needle-like domains, with short range correlations in the ab plane.  Our most recent results, published in PRB, show that the helical pitch length and the ab plane correlation length are intrinsically related to each other – the pitch length appears to set the size of the correlations in the ab plane.  This is reminiscent of Skyrmions, whose size is set by the helical pitch length.