Potential Skyrmion Host Fe(IO3)3: Connecting Stereoactive Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction

Magnetic skyrmions, which are topologically distinct magnetic spin textures, are gaining increased attention for their unique physical properties and potential applications in spintronic devices. Here we present a design strategy for skyrmion host candidates based on combinations of magnetic spin, asymmetric building units having stereoactive lone-pair electrons, and polar lattice symmetry. To demonstrate the viability of the proposed rational design principles, we successfully synthesized a Fe(IO3)(3) polycrystalline sample and single crystals by using a new simplified low-temperature pathway, which is experimentally feasible for extending materials growth of transition metal iodates. Single crystal X-ray and powder synchrotron X-ray diffraction measurements demonstrated that Fe(IO3)(3) crystallizes in the polar chiral hexagonal lattice with space group P6(3). The combined structural features of the macroscopic electric polarization along the caxis stemming from the coalignment of the stereoactive lone-pairs of the IO3- trigonal pyramid and the magnetic Fe' cation residing on the 3-fold rotation axis were selected to promote asymmetric exchange coupling. We find evidence of a predicted skyrmion phase at 14 K <= T <= 16 K and 2.5 T <= mu H-0 <= 3.2 T driven by a Dzyaloshinskii-Moriya (DM) interaction, a conclusion supported by the appreciable DM exchange and the zero-field spiral antiferromagnetic ground state of Fe(IO3), deduced from neutron diffraction experiments. The associated magnetic modulation wavelength of the putative skyrmions is expected to be short similar to 18 nm, comparable to the period of the DM-driven incommensurate order. This work links stereoactive lone-pair electron effects to enhanced DM interaction, demonstrating a new approach for chemical guidelines in the search for skyrmionic states of matter.

Automated summary

This study presents a design strategy for skyrmion host candidates based on magnetic spin and stereoactive lone-pair electrons. By synthesizing Fe(IO3)(3) and observing a predicted skyrmion phase, the researchers demonstrate a link between stereoactive lone-pair electron effects and enhanced Dzyaloshinskii-Moriya interaction, providing a new approach for chemical guidelines in the search for skyrmionic states of matter.