What are spinels and inverse spinel?
The key difference between spinel and inverse spinel structure is that in spinel structure, B ions occupy half the octahedral holes while A ions occupy 1/8th of the tetrahedral holes whereas, in inverse spinel structure, all A cations and half of the B cations occupy octahedral sites and the other half of B cations …
What are inverse spinels?
An inverse spinel is an alternative arrangement where the divalent ions swap with half of the trivalent ions so that the M(II) now occupy octahedral sites. i.e. B(AB)O4. In this case Ni(II) is octahedral and half of the Fe(III) are tetrahedral.
How do you find the spinel and inverse spinel?
“If the BIII ion has more CFSE gain in octahedral site than that of AII ion, a normal spinel structure is expected.” “Whereas an inverse spinel is formed whenever the divalent AII ion has comparatively more CFSE gain in octahedral geometry than the trivalent BIII ion.”
What are different types of spinels?
The spinel group is divided into three immiscible series: the spinel (aluminum-spinel) series, in which B is aluminum; the chromite (chromium-spinel) series, in which B is chromium; and the magnetite (iron-spinel) series, in which B is iron.
What are the normal and inverse spinel?
Mn3O4 is a normal spinel since the Mn2+ ion is a high spin d5 system with zero CFSE. The two Mn3+ ions are high spin d4 with higher CFSE on the octahedral sites (3/5 ΔO) than on the tetrahedral site (2/5 Δt ~ 1/5 ΔO). Fe3O4 is an inverse spinel since the Fe3+ ion is a high spin d5 system with zero CFSE.
Is Fe3O4 inverse spinel?
Co3O4 has a normal and Fe3O4 are inverse spinels. both have normal spinel structure. Co3O4 has a inverse and Fe3O4 are normal spinels.
What are normal and inverse spinels give examples?
- Examples of normal and inverse spinel structures:
- MgAl2O4 is a normal spinel since both Mg2+ and Al3+ are non-transition metal ions and thus CFSE = 0.
- Mn3O4 is a normal spinel since the Mn2+ ion is a high spin d5 system with zero CFSE.
What do you mean by normal and inverse spinel?
Spinel is a name of Mixed Ore of Magnesium(Mg) and Aluminium(Al), its molecular formula is MgAlO4 (MgO.Al2O3). Here Mg is in +2 oxid. state and Al is in +3 oxid. state.
Is magnetite inverse spinel?
The crystal structure of magnetite is inverse spinel with a unit cell consisting of 32 oxygen ions in a face-centered cubic structure and a cell parameter of 0.839 nm. At temperatures above 120K, Fe2+ and half of the Fe3+ occupy octahedral sites and the other half of the Fe3+ occupies tetrahedral sites.
What are different types of spinels give examples?
Members of the spinel group include:
- Aluminium spinels: Spinel: MgAl. 2O.
- Iron spinels: Cuprospinel: CuFe. 2O.
- Chromium spinels: Chromite: FeCr. 2O.
- Cobalt spinels: Manganesecobaltite: Mn. 1.5Co.
- Vanadium spinels: Coulsonite: FeV. 2O.
- Others with the spinel structure: Ringwoodite: (Mg,Fe) 2SiO.
Is Fe3O4 normal or inverse spinel?