Structural phase transitions of the metal oxide perovskites SrTiO3, LaAlO3, and LaTiO3studied with a scree

Abstract

We have investigated the structural phase transitions of the transition metal oxide perovskites SrTiO 3 , LaAlO 3 , and LaTiO 3 using the screened hybrid density functional of Heyd, Scuseria, and Ernzerhof (HSE06). We show that HSE06-computed lattice parameters, octahedral tilts, and rotations, as well as electronic properties, are significantly improved over semilocal functionals. We predict the crystal-field splitting ( CF ) resulting from the structural phase transition in SrTiO 3 and LaAlO 3 to be 3 meV and 10 meV, respectively, in excellent agreement with experimental results. HSE06 identifies correctly LaTiO 3 in the magnetic states as a Mott insulator. Also, it predicts that the GdFeO 3 -type distortion in nonmagnetic LaTiO 3 will induce a large CF of 410 meV. This large crystal-field splitting associated with the large magnetic moment found in the G-type antiferromagnetic state suggests that LaTiO 3 has an induced orbital order, which is confirmed by the visualization of the highest occupied orbitals. These results strongly indicate that HSE06 is capable of efficiently and accurately modeling perovskite oxides and promises to efficiently capture the physics at their heterointerfaces.

High-Throughput Computational Screening of Perovskites for Thermochemical Water Splitting Applications

“…This result is in agreement with the observation that the B-site atom is almost always smaller the A-site atoms in the perovskite structure as it is embedded in a rigid octahedron of oxygen. [73][74][75] Additionally, we see very few compounds containing transition metals (rows labeled 3d, 4d and 5d in Figure 5) on the A-site, probably for a similar reason: transition metals are generally smaller than the other elements and thus preferentially tend to occupy the B-site. Conversely, most of the perovskites predicted to be stable in the undistorted cubic geometry contain bigger elements such as alkali and alkaline-earth metals (Li, Be, Na, Mg, K, Ca, Rb, Sr, Cs and Ba) on the A-site.…”

Rare‐Earth Dopant Effects on the Structural, Energetic, and Magnetic Properties of Alumina from First Principles

“…Additionally, comparative studies between the semi‐local functionals and the hybrid functionals (e.g. HSE06), with self‐interaction correction schemes, revealed an improvement in the electronic description from the semi‐local functionals, but little or no difference in the structural properties and total energies between these functionals . Because the objective of this study was to examine energetic and structural properties of Ln‐doped Al 2 O 3 , the GGA functional was expected to provide a qualitative understanding of these properties.…”

Hydrogen Bonding and Stability of Hybrid Organic–Inorganic Perovskites

“…[58,59] Below 0.80, other structures, such as the ilmenite-type (FeTiO 3 ), are more stable owing to similar sizes of the cationsAandB ,a nd values larger than 1l ead to hexagonal structures where layerso ff ace-sharing octahedra are introduced into the structure. [61] It was experimentallys hown that tunable optical bandgaps in metal-halide perovskites could be achievedb yc ontrolling the degree of the PbI 6 octahedral tilting through the steric size of the molecular cation. They generate lower-symmetry distorted structures, in which the coordination numberso fAcations, Bc ations, or both are reduced.…”