Theoretical analysis on O vacancy and cation inversion in NiCo2O4

Fabrication of dual-functional electrodes using oxygen vacancy abundant NiCo2O4nanosheets for advanced hybrid supercapacitors and Zn-ion batteries

“…S5 †). 29 The optimized atomic structure models of NiCo The localized electrons are presented by the red area, which suggests that oxygen ions are relatively much more localized than the metal ions in an ionic crystal. The interaction between metal atoms and neighboring oxygen atoms is also discussed, which is shown in the shape and distribution of atomic orbitals and electron density difference images (Fig.…”

“…S5†). 29 The optimized atomic structure models of NiCo 2 O 4 and V-NiCo 2 O 4 -4 are shown in Fig. S6 †.…”

Epitaxial NiCo2O4 film as an emergent spintronic material: Magnetism and transport properties

“…47 Chemical disorders such as cation/oxygen vacancies, valence disorder, and cation inversion can have significant impacts on the electronic and magnetic properties of NCO. 93 In this section, we discuss the effects of cation stoichiometry, valence, and site occupancy on the observed property variation.…”

Enrichment of the field emission properties of NiCo2O4 nanostructures by UV/ozone treatment

“…Also, the higher Ni 3+ / Ni 2+ atomic ratio for UV/O3 treated NiCo2O4 indicates the formation of defects due to oxygen vacancies at the surface[41][42]. The O defects that are formed may be attributed to B-type of oxygen vacancy as the charge balance is counted by partial substitution Ni 3+ for Ni 2+ at the octahedral B-sites which indicates the lowered interaction of Ni-O vacancy with octahedral Ni and increased interaction between tetrahedral Ni and O[38,[55][56][57]. Relatively no much change in the atomic ratio of Co 2p spectra is observed.…”

“…Whereas the short time exposure (20-30s) occupies the Oxygen vacancy defects on the surface and creates interstitial species [53,54]. Most commonly in spinel's oxygen vacancy and cation inversion (change in valance state of cations) are the main factors that lead to change in their properties [55,56]. The present article aims the UV/O3 treatment on the NiCo2O4 to improve the FE properties.…”