Tailoring imprint in ferroelectric thin films through substrate work function

The imprint effect, one of the most critical parameters in ferroelectrics, manifests as an asymmetry in polarization reversal. The precise control of imprint is essential for reliable implementations of ferroelectric materials in many applications. In this study, we demonstrate that imprint can be tuned in Bi2FeCrO6 (BFCO) thin films by changing the nature of the underlying layer. Specifically, BFCO(111) films deposited on Nb-doped SrTiO3 (Nb:STO) and SrRuO3 (SRO) exhibit distinct imprint characteristics. Piezoresponse force microscopy reveals a consistent imprint difference of about 1 V between BFCO/Nb:STO and BFCO/SRO, which correlates with the work function difference between the two substrates. These findings underscore a generalizable mechanism for imprint control in ferroelectric heterostructures and hold particular relevance for applications demanding fine polarization management.