Fig. 1: Polarization suppression from competitive interfaces.
From: In-situ monitoring of interface proximity effects in ultrathin ferroelectrics
a ISHG signal tracking the PTO thin-film polarization during ongoing (filled red symbols, 0–8 u. c.) and halted (filled black symbols) growth. The time axis for this growth protocol reveals relaxation of the polarization on the order of 102 s. The inset shows the chemistries of interfacial planes at the PTO∣LSMO interface and the polarization direction set by the bottom interface. The dashed line indicates recovery of the ISHG intensity upon resuming the deposition. b Time-dependent ISHG signal after interrupting deposition, normalized to the maximum value = 100. c Post-deposition STEM map of the dipole moments. The arrows show the direction (color wheel) and amplitude (arrow length) of the associated dipole moments (top). Scale bar is 1 nm. The OOP B-site displacement (δB) of the persistent state is mapped throughout the PTO∣LSMO bilayer (bottom). Black symbols refer to LSMO, red and blue symbols refer to upwards and downwards polarization, respectively, in PTO. The error bars are the standard error of the mean. The electrostatic boundary conditions at the La0.7Sr0.3O∣TiO2-terminated LSMO∣PTO interface result in the observed displacement discontinuity, see main text and ref. 16.
