1. (a) XRD patterns of PMN-PT/SRO/GSO and PZT/SRO/GSO heterostructures, where PMN-PT and PZT are both 100 nm thick, in which the * symbols indicate the (00l) Bragg reflections peaks of GSO, with insets showing the AFM surface morphologies of GSO substrate, SRO/GSO, PMN-PT(5 nm)/SRO/GSO, PMN-PT(100 nm)/SRO/GSO thin-film heterostructures; (b) Cross-sectional STEM image and elemental distributions of the 5 nm thick PMN-PT/SRO/GSO heterostructure; (c) HAADF image of the PMN-PT layer

S1. Surface morphologies, PFM amplitudes and phase images of 100 nm-thick PZT and PMN-PT thin films

2. Polarization-electric field hysteresis loops of PZT (a) and PMN-PT (b) thin-film capacitors with different thicknesses

S2. S2 PFM hysteresis loops of 100 nm-thick PMN-PT films

S3. PFM hysteresis loops of STO crystal

3. PFM hysteresis characterizations on PZT and PMN-PT thin-film heterostructures with different thicknesses

S4. (a) PMN-PT/SRO/GSO and (b) PMN-PT/SRO/STO PFM read/write domain characterizations

4. PFM hysteresis loops of 5 nm-thick PMN-PT films on various substrates

S5. PFM hysteresis loops of PMN-PT films with different thicknesses

5. PFM hysteresis loops of PMN-PT/SRO/STO heterostructures with different thicknesses