Topic:
Scientific Achievement
Discovered quadruple-well ferroelectricity in layered CuInP2S6 crystals based on a structural phase that doubles electrostatic polarization enabled by the van der Waals gap.
Significance and Impact
The quasi-2D crystal structure of this material enables new trajectories for atomic motion toward new physical behaviors and new classes of ferroelectric devices.
Research Details
- Theory predicted a quadruple potential well for Cu displacements. Piezoelectric force microscopy detected all four states.
- The quadruple potential well is tuned by strain, leading to phase co-existence under inhomogeneous strain.
- The Cu position can be locally controlled by bias or pressure enabling the switching between them.
J. A. Brehm, S. Neumayer, L. Tao, A. O’Hara, M. Chyasnavichus, M. A. Susner, M. A. McGuire, S. V. Kalinin, S. Jesse, P. Ganesh, S. T. Pantelides, P. Maksymovych, N. Balke, Tunable quadruple-well ferroelectric van-der-Waals crystals, Nat. Mater., accepted (2019). DOI: 10.1038/s41563-019-0532-z
