Investigation of incommensurate structures in β-NaFeO2

β-NaFeO2 has attracted attention as a candidate for multiferroic at room temperature because of its ferroelectric crystal structure and antiferromagnetic ordering at room temperature. However, the crystal structure as well as the magnetic structure remain unclear. To establish a proper symmetry for crystal and magnetic structure we have proposed a neutron powder experiment using WISH instrument (Proposal Reference No: 2420045). Additionally, our magnetization measurements for β-NaFeO2 single crystal show an indication of new antiferromagnetic transitions below 120 K. Due to the magnetoelectric couplings associated with those transitions, an incommensurate structure might be established and might correlate to the multiferroic properties in β-NaFeO2. Here, we propose a single crystal diffraction experiment to verify the existence of incommensurate structures between the antiferromagnetic orderings at low temperatures. The result will be useful for understanding the magnetoelectric coupling supporting multiferroic systems, particularly NaFeO2 compounds.