Emerging ferroelectricity in elemental system

Abstract Elemental ferroelectrics, composed of a single element, have emerged as a new class of functional materials that offer distinct advantages of structural simplicity and compositional purity. Though elemental systems are typically stabilized in nonpolar, high-symmetry structures, ferroelectricity can be induced through various mechanisms including lattice distortions and interlayer charge redistribution that break centrosymmetry and drive the system into a polarized state. Both theoretical predictions and experimental demonstrations have revealed ferroelectric behavior in diverse elemental systems, with some exhibiting unique properties, including significant negative piezoelectric effects and stable charged domain walls. These findings not only advance fundamental understanding of ferroelectric mechanisms but also open new opportunities for novel ferroelectric applications.