Electric‐Field Manipulation of Magnetic Chirality in a Homo‐Ferro‐Rotational Helimagnet

Ferro‐rotational (FR) materials, renowned for their distinctive material functionalities, present challenges in the growth of homo‐FR crystals (i.e., single FR domain). This study explores a cost‐effective approach to growing homo‐FR helimagnetic RbFe(SO4)2 (RFSO) crystals by lowering the crystal growth temperature below the TFR threshold using the high‐pressure hydrothermal method. Through polarized neutron diffraction experiments, it is observed that nearly 86% of RFSO crystals consist of a homo‐FR domain. Notably, RFSO displays remarkable stability in the FR phase, with an exceptionally high TFR of ≈573 K. Furthermore, RFSO exhibits a chiral helical magnetic structure with switchable ferroelectric polarization below 4 K. Importantly, external electric fields can induce a single magnetic domain state and manipulate its magnetic chirality. The findings suggest that the search for new FR magnets with outstanding material properties should consider magnetic sulfates as promising candidates. This study investigates the cost‐effective growth of homo‐FR RbFe(SO4)2 crystals, showcasing their stability in the FR phase at 573 K. Neutron diffraction reveals 86% of a homo‐FR domain. Its helical magnetic structure and switchable ferroelectric polarization are explored, along with the potential for electric field‐induced chiral magnetic domain control. Promising sulfates as FR materials are highlighted.