This study demonstrates the first synthesis of MXene-derived ferroelectric crystals. Specifically, high-aspect-ratio potassium niobate (KNbO3 ) ferroelectric crystals is successfully synthesized using 2D Nb2 C, MXene, and potassium hydroxide (KOH) as the niobium and potassium source, respectively. Material analysis confirms that a KNbO3 orthorhombic phase with Amm2 symmetry is obtained. Additionally, ferroelectricity in KNbO3 is confirmed using standard ferroelectric, dielectric, and piezoresponse force microscopy measurements. The KNbO3 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.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: S.T. and F.M. contributed equally to this work. Research reported in this publication is supported by King Abdullah University of Science and Technology (KAUST). The high-resolution TEM analysis was completed individually by J.Z. The authors would like to thank Dr. Daliang Zhang, Dr. Xin He, and Dr. Fei Xue for their helpful discussion, and the Advanced Nanofabrication, Imaging and Characterization Laboratory at KAUST for their support.