Growth and structural characterization of strained epitaxial Hf0.5Zr0.5O2 thin films

Ferroelectricity was recently reported in thin films with several compositions in the HfO2-ZrO2 system with orthorhombic crystal structure. In the present paper we study the growth by pulsed laser deposition and the structural characterization of strained epitaxial Hf0.5Zr0.5O2 films on (001)-oriented yttria-stabilized zirconia (YSZ) substrates. We have determined the conditions for the coherent growth and correlated the deposition parameters with the films structure andmicrostructure studied through a combination of x-ray diffraction, electron backscatter diffraction, and scanning transmission electron microscopy. In the range of experimental parameters explored, all the films show monoclinic structure with distorted lattice parameters relative to bulk.