Fig. 1: Epitaxial engineering of robust high-spin ferrous oxides.
From: From Slater to Mott physics by epitaxially engineering electronic correlations in oxide interfaces
a Illustrative band diagrams of constituent materials LaTiO3, LaFeO3 and the superlattice. The dashed black lines are the aligned Fermi levels. The black arrow indicates the direction of the transferred charge when forming the superlattice. b The magnetic phase histogram predicted by spin-assisted ab initio random structure searches of the LaTiO3/LaFeO3 superlattice clamped to the LaAlO3 substrate. The reference structure is the fully relaxed bulk LaAlO3 antiferromagnetic LaTiO3/LaFeO3 superlattice in the high-spin configuration. The phase space is categorised into four different types of magnetic configurations and is ordered by energy. c Orbital resolved density of states for Fe1(3d) and O ((2p)) majority (positive y-axis) and minority (negative y-axis) spin-species at the LaTiO3/LaFeO3 (1/1) superlattice. d Relative energy (ER = Esub − Ebulk) stability with respect to the bulk superlattice of the Fe2+(S = 2) antiferromagnetic ground state (red star symbols). Across different epitaxial oxide substrates, a rich set of solutions is provided: charge transfer with Fe2+ in (i) low-spin (CT LS), (ii) high-spin antiferromagnetic (CT HS AF), (iii) ferromagnetic (CT HS F) configuration and (iv) no charge transfer (NO CT). The star symbols represent the different solutions for the configuration-dependent ground states heterostructures in absence of any in-plane strain.
