MXene-Derived Ferroelectric Crystals

Abstract

This study demonstrates the first synthesis of MXene-derived ferroelectric crystals. Specifically, high-aspect-ratio potassium niobate (KNbO 3 ) ferroelectric crystals is successfully synthesized using 2D Nb 2 C, MXene, and potassium hydroxide (KOH) as the niobium and potassium source, respectively. Material analysis confirms that a KNbO 3 orthorhombic phase with Amm2 symmetry is obtained. Additionally, ferroelectricity in KNbO 3 is confirmed using standard ferroelectric, dielectric, and piezoresponse force microscopy measurements. The KNbO 3 crystals exhibit a saturated polarization of ≈21 µC cm −2 , a remnant polarization of ≈17 µC cm −2 , and a coercive field of ≈50 kV cm −1 . This discovery illustrates that the 2D nature of MXenes can be exploited to grow ferroelectric crystals.