Elastic properties of rhombohedral, cubic, and monoclinic phases of LaNiO 3 by first principles calculations

Abstract

By applying density functional theory (DFT) approximations, we present a firstprinciples investigation of elastic properties for the experimentally verified phases of a metallic perovskite LaNiO 3 . In order to improve the accuracy of calculations, at first we select the most appropriate DFT approaches according to their performance in reproducing the low-temperature crystalline structure and the electronic density of states observed for the bulk LaNiO 3 . Then, we continue with the single-crystal elastic constants and mechanical stability for the most common rhombohedral as well as high-temperature cubic and strain-induced monoclinic phases. Together with the calculated single-crystal elastic constants, the deduced polycrystalline properties, including bulk, shear, and Young's moduli, Poisson's ratio, Vickers hardness, sound velocities, Debye temperature, and anisotropy indexes, remedy the existing gap of knowledge about the elastic and mechanical behaviour of LaNiO 3 , at least from a theoretical standpoint.

Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures

“…Based on this relationship, the Poisson ratio was estimated to be 0.44 and 0.35 for our PMN-PT substrates and NNO films, respectively. It should be noted that the Poisson ratios ( ) of the PMN-PT (001) and LaNiO 3 have been reported to be 0.46 37 and ~0.3 39 in the previous literatures, respectively, confirming that our lattice parameter modulation results from mechanical response by piezoelectric strain in the each PMN-PT and NNO layer. Furthermore, there is negligible change of unit-cell volume (0.0568 nm −3 to 0.0566 nm −3 ) of NdNiO 3 after the application of electric field ( Table S3 in Supplementary Information ), providing direct evidence that field-controlled piezoelectric strain does not influence the defect concentration and thus field-induced strain are able to modulate only band-width by the elastic coupling without changing the concentration of defects.…”

Tuning Bifunctional Oxygen Electrocatalysts by Changing the A‐Site Rare‐Earth Element in Perovskite Nickelates

“…Dark blue stars represent the pseudocubic lattice constants for bulk LNO, NNO, SNO, and GNO . Open black squares represent the strained OOPs of RNO films estimated from the Young's modulus by taking into account the Poisson's ratio v ≈ 0.34 …”

Thickness-Dependent Perovskite Octahedral Distortions at Heterointerfaces

“…Bulk lattice parameters for all materials are denoted by the black dashed line. The wider dashed lines show the film c -axis parameters that would be expected for a given heterointerface assuming only a volume change governed by the Poisson ratio (ν LNO = 0.34 from ref (39) and ν LAO = 0.22 from ref (40)). Error bars derive from the reliability of fitting the finite thickness fringes in InteractiveXRDFit, which increases with film thickness.…”