Domain matching epitaxy of ferroelectric Hf0.5Zr0.5O2(111) on La2/3Sr1/3MnO3(001)

S. Estandía, N. Dix, M.F. Chisholm, I. Fina, and F. Sánchez

Crystal Growth & Design 20, 3801 (2020)

DOI: 10.1021/acs.cgd.0c00095

Abstract

Epitaxial ferroelectric HfO₂ films are the most suitable to investigate intrinsic properties of the material and for prototyping emerging devices. Ferroelectric Hf_0.5Zr_0.5O₂(111) films were epitaxially stabilized on La_2/3Sr_1/3MnO₃(001) electrodes. This epitaxy, considering the symmetry dissimilarity and the huge lattice mismatch, is not compatible with conventional mechanisms of epitaxy. To gain insight into the epitaxy mechanism, scanning transmission electron microscopy characterization of the interface was performed, revealing arrays of dislocations with short periodicities. These observed periodicities agree with those expected for domain matching epitaxy, indicating that this unconventional mechanism could be the prevailing factor in the stabilization of ferroelectric Hf_0.5Zr_0.5O₂ with (111) orientation in the epitaxial Hf_0.5Zr_0.5O₂(111)/La_2/3Sr_1/3MnO₃(001) heterostructure.