Structure of epitaxial Mn-stabilized ZrO2 layers on yttria-stabilized zirconia single crystals prepared by sputtering

Epitaxial Mn-stabilized zirconia layers on yttria-stabilized ZrO2 (YSZ) single crystals were prepared by sputtering a Mn0.32Zr0.68O2 target. Substrates with (001), (110) and (111) orientation were used. Transmission electron microscopy cross sections showed a homogeneous thickness of the layers. Layers prepared at a substrate temperature of 600 °C grew epitaxially. X-ray diffraction showed that these layers are not exactly cubic. We found a slightly larger out-of-plane lattice parameter compared to the in-plane lattice parameter. This means the out-of-plane lattice misfit is lower than the in-plane lattice misfit, contrary to behaviour expected for epitaxially grown layers. This effect was largest for layers on YSZ(111) and small for layers on YSZ(001).