Exchange interactions in NiO and at the NiO(100) surface

Abstract

The electronic and magnetic structure of bulk NiO and the NiO͑100͒ surface is calculated using densityfunctional theory ͑DFT͒ in the local-spin-density ͑LSD͒ approximation including self-interaction corrections. We calculate the exchange coupling constants in bulk NiO and at the NiO͑100͒ surface and show that in the case of bulk they agree better with experiment than the standard DFT calculations in the LSD approximation. We develop a model for the exchange interactions at the NiO͑100͒ surface and discuss how they change from the surface to bulk.

Ab initio charge, spin and orbital energy scales in LaMnO 3

“…The energy scale that characterises the stability of A-AFM versus FM is the smallest energy scale, at ∼ 1 mRy, which is similar to energies that gave correct exchange constants for NiO(100) surface. [10] Thus, the ordering sequence of the rows will be the same for the A-AFM and the FM structures, which indicates that the dominant cause of the orbital ordering is not the A-AFM magnetic structure, as has been postulated. [11,12] It is instructive to see how far a localized model that assumes only a locally pure tetragonal distortion can account for the ab initio results.…”

Exchange interactions, spin waves, and transition temperatures in itinerant magnets

“…The simplest approach lies in obtaining the exchange interactions from total-energy differences calculated directly for various (usually collinear) spin configurations [85,145,146]. The usefulness of such schemes is, however, rather limited mainly due to a finite number of configurations used for the mapping.…”

“…The usefulness of such schemes is, however, rather limited mainly due to a finite number of configurations used for the mapping. This fact together with the asymptotic behaviour of the exchange interactions (12, 13) make the simple mapping procedures suitable especially for non-metallic systems (half-metals, in- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 F o r P e e r R e v i e w O n l y sulators) with short-ranged exchange interactions [146,147].…”

Exchange interactions in transition metal oxides: the role of oxygen spin polarization

“…The simple rock-salt structure along with the inability of regular DFT functionals to correctly describe these materials, make NiO and MnO typical benchmark systems to test methods for the calculation of exchange interactions in strongly correlated systems. Beyond the DFT methods such as LDA+U, [34,44,45] hybrid functionals, [46,47] the self-interaction correction, [41,48] GW approximation [49] and dynamical mean-field theory [42,50] have been used successfully to improve the correspondence between calculations and experiments in these materials. [34,42,46,47] In contrast, LSIC overestimates the electron localization, leading to a slight underestimation of the exchange interactions.…”