Figure 1 : High-mobility 2DEGs at epitaxial spinel/perovskite γ-Al2O3/STO interfaces.

From: A high-mobility two-dimensional electron gas at the spinel/perovskite interface of γ-Al2O3/SrTiO3

Figure 1

(a) A sketch of the heterostructure. (b) Oxygen sublattices as the backbone to build the spinel/perovskite heterostructure. The compatibility in oxygen sublattices of a γ-Al2O3 surface and the TiO2-terminated STO surface is shown in c and d, respectively. Of note, the tetrahedral cation sites in γ-Al2O3 are not shown. (e) Typical RHEED intensity oscillations for the growth of a 3-uc γ-Al2O3 on STO in a subunit cell layer-by-layer mode. (f) HAADF STEM image of the epitaxial γ-Al2O3/STO interface. Scale bar, 1 nm. Sr ions are brightest, followed by Ti. The faintly visible Al elements can be determined by the averaged line profiles across the interface shown in g. A well-developed TiO2-AlOx heterointerface is defined.