Robust ferroelectricity in epitaxial Hf1/2Zr1/2O2 thin films

Ferroelectric orthorhombic Hf0.5Zr0.5O2 thin films have been stabilized epitaxially on La2/3Sr1/3MnO3/SrTiO3(001) by pulsed laser deposition. The epitaxial orthorhombic films, (111)-oriented and with a very flat surface, show robust ferroelectric properties at room temperature. They present a remnant polarization around 20 μC/cm2 without the need of a wake-up process, a large coercive electric field of around 3 MV/cm, an extremely long retention extending well beyond 10 years, and an endurance up to about 108 cycles. Such outstanding properties in the nascent research on epitaxial HfO2-based ferroelectric films can pave the way for a better understanding of the effects of orientation, interfaces, strain, and defects on ferroelectricity in HfO2.