Ab initio simulation of the short‐range order structure of Al ions and substitutional Fe, Cr impurities in S.S. Spinel (MgAl₂O₄)

Abstract

ABSTRACT:The structure of the short-range surrounding of aluminum, ferric iron and Me are displaced considerably relative to the initial ideal structure. The displacement depends on the central cation of the cluster. The estimated short-range order parameters including the oxygen parameter u of the spinel are in satisfactory agreement with experimental data. Comparable analysis of the electronic structure of Al, Fe, Cr cations in octahedral positions of the spinel in ideal and relaxed clusters showed that octahedral distortions should be taken into account when interpreting spectroscopic parameters of the natural spinels and evaluating the charge balance in their structure.

Structural relaxation around substitutionalCr3+inMgAl2O4Juhin1, Calas2, Cabaret3 et al. 2007Phys. Rev. B541340View full textAdd to dashboardCite

“…Our firstprinciples calculations also agree with a previous investigation of the first shell relaxation, using Hartree-Fock formalism on an isolated cluster. 33 As it has been mentioned previously, the simulation can provide complementary distances (Fig. 3b) (Fig.…”

Structural relaxation around substitutional Cr3+ in MgAl2O4

“…Our firstprinciples calculations also agree with a previous investigation of the first shell relaxation, using Hartree-Fock formalism on an isolated cluster. 33 As it has been mentioned previously, the simulation can provide complementary distances (Fig. 3b The experimental XANES spectrum of natural MgAl 2 O 4 : Cr 3+ is shown in Fig.…”