Observation of magnetic-field-induced ferroelectricity in a compound CaFe3O(PO4)3

Geometrically frustrated kagome materials reveal many novel states of matter ranging from quantum spin liquids to multiferroics. Herein, we study the compound CaFe3O(PO4)(3), which has a quasi-two-dimensional lattice of Fe3+ ions with spin S = 5/2. Electrical and magnetic properties have been investigated on polycrystalline specimens of CaFe3O(PO4)(3) using magnetization, pyroelectric, and magnetoelectric current measurements. The system undergoes a weak ferromagnetic-type ordering at T-C1 similar to 19.5 K, followed by another transition at T-C2 similar to 9 K. While no ferroelectric polarization (P) is observed at a zero magnetic field (H), the applied H induces P below T-C2. At the temperature of 2.5 K, P starts to increase above H of 1 T, shows a maximum value at 3.15 T, and then decreases at higher H regions. The observed results suggest that CaFe3O(PO4)(3) should be a magnetic-field-induced ferroelectric compound with frustrated magnetic couplings.

Automated summary

In this study, we investigated the geometrically frustrated kagome material CaFe3O(PO4)(3), which exhibits various novel states of matter. Through magnetization, pyroelectric, and magnetoelectric current measurements, we studied the electrical and magnetic properties of CaFe3O(PO4)(3). The system undergoes weak ferromagnetic-type ordering at T-C1 around 19.5 K, followed by another transition at T-C2 around 9 K. While no ferroelectric polarization is observed at zero magnetic field, it is induced below T-C2 with the application of a magnetic field. At 2.5 K, the ferroelectric polarization starts to increase above a magnetic field of 1 T, reaches a maximum value at 3.15 T, and then decreases at higher magnetic fields. These observations suggest that CaFe3O(PO4)(3) is a magnetic-field-induced ferroelectric compound with frustrated magnetic couplings.