Figure 1
From: Structural characterisation of high-mobility Cd3As2 films crystallised on SrTiO3
Epitaxial relation between Cd3As2 and SrTiO3. (a) Top and (b) side views of crystal structures, representing epitaxial [112] Cd3As2/[001] SrTiO3 relation. The green hexagons in (a) represent the As triangular lattice in Cd3As2. There are two possible in-plane alignments on the Ti square lattice (right). (c) HAADF-STEM image showing atomic arrangement at the heterointerface between Cd3As2 film and SrTiO3 substrate. (d) Depth profile of Cd, As, Sr, Ti, and O, obtained by integrating EDX counts along the horizontal direction in (c). Incidentally, Sr EDX counts in the depth profile are certainly suppressed in the interfacial layers as compared to the respective Ti and O results, indicating that a few TiO2 layers are formed by high-temperature annealing29,30. The STEM and EDX measurements were performed with a low acceleration voltage of 80 kV to reduce the damage at the Cd3As2 interface, resulting in the lower resolution image compared to those of the central region26 taken at 200 kV. The damage is inevitable to some extent, causing deviation from the Cd/As stoichiometric composition at the interface. (e) Epitaxial relation of the (112) oriented Cd3As2 film on the (001) SrTiO3 substrate. Projected lattice distances of the triangular-lattice As atoms and the square-lattice Ti atoms are almost the same.
