${[{\mathrm{BaTiO}}_3]}_m/{[{\mathrm{BaZrO}}_3]}_n$ ($m$, $n=4–12$) superlattices are used to demonstrate the fabrication and deterministic control of an artificial relaxor. X-ray diffraction and atomic-resolution imaging studies confirm the production of high-quality heterostructures. With decreasing ${\mathrm{BaTiO}}_3$ layer thickness, dielectric measurements reveal systematically lower dielectric-maximum temperatures, while hysteresis loops and third-harmonic nonlinearity studies suggest a transition from ferroelectriclike to relaxorlike behavior driven by tuning the random-field strength. This system provides a novel platform for studying the size effect and interaction length scale of the nanoscale-polar structures in relaxors.

• Received 27 November 2022
• Accepted 9 May 2023

DOI:https://doi.org/10.1103/PhysRevLett.130.266801