Ab initio study of the role of defects on the magnetic response and the structural, electronic and hyperfine properties of ZnFe2O4

Abstract

Ab initio study of the role of defects on the magnetic response and the structural, electronic and hyperfine properties of ZnFe 2 O 4 . `

Ab-initio approach to the stability and the structural, electronic and magnetic properties of the (001) Znfe2O4 surface terminations

“…For both O 4 -Fe 4 and O 4 -Fe 4 -O 4 terminations no spin-polarization was found at the Zn-sites while spin-polarization in the order of 0.15 μ B was found for some oxygen atoms (a similar result was obtained in reduced ZnFe 2 O 4 , see Ref. [36]).…”

“…A similar effect was found in reduced bulk ZnFe 2 O 4 . In this case, the formation of an oxygen vacancy reduce the magnitude of the magnetic moments of the three Fe atoms nearest neighbors to the vacancy sites to from 4.2 μ B [17] to 4.0 μ B Fe atoms) and −3.6 μ B for the remaining one [36]. The Fe atoms located in layers 2.3 Å (at least) below the surface present magnetic moments in the order of 4.1-4.2 μ B .…”

“…The basis set size and muffin-tin radii were taken as in the case of the bulk system (Refs. [17] and [36]).…”

“…To validate whether it is legitimate to use QE results, we examine whether they correctly reproduce FP-LAPW calculations. Exchange and correlation effects were also treated within density-functional theory using the GGA+U in the SIC formalism [33] with U = 5 eV for the Fe-3d orbitals [17,36]. A 2 × 2 × 1 k-point mesh was employed to sample the first Brillouin zone.…”

Stabilizing Oxidative Dehydrogenation Active Sites at High Temperature with Steam: ZnFe2O4-Catalyzed Oxidative Dehydrogenation of 1-Butene to 1,3-Butadiene

“…An antiferromagnetic spin arrangement ( Figure S1) was found to correspond to the lowest energy, which is in consistent with reported results. 47,48 The synthesized ZnFe 2 O 4 catalyst was imaged via scanning tunneling electron microscopy (STEM). 49,50 The HAADF-STEM image ( Figure 1) revealed that in perpendicular sections the two in plane directions are [110] and [001], which indicates that the sample was inspected from the [110] direction.…”