Fig. 3: Ferroelectric characterizations of HZO/STO(110) films.
From: Interface-controlled uniaxial in-plane ferroelectricity in Hf0.5Zr0.5O2(100) epitaxial thin films
a Schematic diagram and optical microscopic image of the HZO(10 nm)/STO(110) film with interdigitated Pt electrodes for the in-plane FE characterizations. b, c Electric field-dependent in-plane polarization (Pin-E) hysteresis loops measured from the HZO(10 nm)/STO(110) film with E//HZO[001]O (b) and E//HZO[010]O (c). The E scanning range (Emax) varies from 0.5 to 0.9 MV/cm. d E-dependent out-of-plane polarization (Pout-E) hysteresis loops measured from the 10 nm thick HZO film grown on Nb:STO(110) substrate. The E scanning range (Emax) varies from 2.0 to 6.0 MV/cm. The inset displays the measurement geometry. The top electrodes are circular-shaped Pt pads. e Left panel: Schematic diagram of switching the in-plane FE polarization through the tip-induced trailing field. The bias applied on the PFM tip (Vtip) is ±7 V. Right panel: Schematic diagram for PFM measurements on uniaxial polarization of HZO(100)O/STO(110) sample. The angle between PFM slow-scan axis and HZO[001]O axis is defined as θscan. In-plane PFM phase (f) and amplitude (g) images with θscan = 0°, 45°, 60°, and 90°. The scanning area is 4 × 4 μm2.
