Ferroelectric Hf0.5Zr0.5O2 thin films deposited epitaxially on (110)-oriented SrTiO3

Hf0.5Zr0.5O2 (HZO) thin films have been deposited on (110)-oriented SrTiO3 (STO) substrates buffered with epitaxial La0.7Sr0.3MnO3 (LSMO) by pulsed laser deposition. The HZO/LSMO/STO heterostructures show smooth surface and clear interface. It is observed that ferroelectric orthorhombic HZO is enhanced, as non-polar tetragonal HZO is suppressed with the increasing LSMO thickness or decreasing HZO thickness. Completely orthorhombic HZO films are achieved with desired LSMO and HZO thickness. These HZO films are (111)-oriented with in-plane [(2) over bar 11] and [0 (1) over bar1] directions along LSMO [1 (1) over bar0] and [001], respectively, and exhibit ferroelectric properties at room temperature with an optimized remanent polarization around 26 mu C/cm(2) without the need of a wake-up process, a long retention up to 10(4) s and a fatigue endurance up to 10(9) cycles. Epitaxial HfO2-based films with robust ferroelectric properties deposited on (110)-oriented STO substrates provide additional opportunities to understand the profound effects of orientation, strain, and interface microstructures on the metastable polar phases and ferroelectric properties of HfO2 thin films. Published under an exclusive license by AIP Publishing.

Automated summary

Deposited Hf0.5Zr0.5O2 (HZO) thin films on (110)-oriented SrTiO3 (STO) substrates buffered with epitaxial La0.7Sr0.3MnO3 (LSMO) by pulsed laser deposition exhibit enhanced ferroelectric properties without the need for a wake-up process, providing insights into the effects of orientation, strain, and interface microstructures on metastable polar phases and ferroelectric properties.