Figure 4
From: Interfacial stabilization for epitaxial CuCrO2 delafossites
(a) Formation enthalpy (ΔHf) of Cr-based delafossite-related materials estimated by DFT-based fitted elemental-phase reference energies (FERE) method. Structural information of PdAlO2 with delafossite symmetry (R\({\overline{3}}\)m or P63/mmc space group) was considered to compare with other delafossites, but the information is absent in the Inorganic Crystal Structure Database (ICSD). (b) Schematics of top and cross-sectional views of a CuCrO2/Al2O3 heterostructure, describing the layer-by-layer growth of a CuCrO2 thin film on an Al2O3 substrate with an atomic-layer thick CuCr1−xAlxO2 nucleation layer. The top view of the top-most surface layer is illustrated on each schematic; Cu atoms are not included in the top view of the surface layer for clear visualization of symmetry matching between delafossite and corundum structures. The MLs of CuCrO2 and Al2O3 are denoted by blue- and green-outlined rectangles on the right side of (b), respectively.
