ChengMo

Nature, Published online: 05 April 2023; doi:10.1038/s41586-023-05848-5

A single-element ferroelectric state is observed in a black phosphorus-like bismuth layer, in which the ordered charge transfer and the regular atom distortion between sublattices happen simultaneously and ferroelectric switching is further visualized experimentally.

A bismuth samarium oxide thin film on a substrate maintains its ferroelectricity at a thickness of only 1 nanometer.