Room-temperature multiferroicity in van der Waals Fe-doped SnSe semiconductors

Abstract

Two-dimensional materials hosting multiple ferroic orders are highly desirable for next-generation electronic and spintronic technologies. However, achieving stable and tunable ferroic functionalities at room temperature remains a key challenge. Here, we report the growth of van der Waals (vdW) Fe-doped SnSe semiconductor that can be exfoliated down to thin layered flakes. These crystals exhibit tunable ferromagnetism well above room temperature, with the Curie temperature increasing from 342 to over 400 K through controlled Fe incorporation. In parallel, anomalous Hall measurements reveal interfacial spin polarization at the SnSe/Pt interface driven by magnetic proximity effects, enabling spin-dependent magnetotransport. Furthermore, robust ferroelectric behavior at room temperature is confirmed by piezoresponse force microscopy. Although the ferromagnetic and ferroelectric orders coexist within the same material system, they originate from distinct mechanisms without direct magnetoelectric coupling. The semiconducting nature of Fe-doped SnSe is supported by both theoretical and experimental analyses, which further enhances its multifunctionality. These results establish Fe-doped SnSe as a versatile vdW platform for integrating magnetic, electric, and electronic functionalities in future energy-efficient devices.