Fig. 5: Stability of net polarization in a STO∣PTO heterostructure.
From: In-situ monitoring of interface proximity effects in ultrathin ferroelectrics
a, b SHG anisotropy plots of STO∣PTO bilayers after cooling to room temperature, shown on the same intensity scale. Data were obtained by simultaneously varying the angle β of the polarization of the incident fundamental and of the detected SHG light at 1200 and 600 nm, respectively. The simulations, see “Methods,” are plotted as continuous lines. Note that for the competitive interfaces (a), a measurable signal is not detected. c, d Logarithmic histogram plots showing the number of occurrences NSTO (black) and NPTO of OOP and in-plane (IP) B-site displacement (δB) measured in post-deposition STEM images for the (c) competitive (red) and the (d) cooperative (blue) interface configuration. The zero net value of B-site displacement in the OOP direction of the competitive case in the multidomain state is the result of polarization averaging across the thickness of the lamella. e Post-deposition STEM map of PTO dipole moments after STO capping in the cooperative configuration. The arrows show the direction (color wheel) and amplitude (arrow length) of the dipole moments. Scale bar is 1 nm.
