The question asks us to determine the cations that can occupy specific positions in the structure of an inverse spinel \(AB_2O_4\). To solve this, we need to understand the structural characteristics and the ionic arrangement in an inverse spinel.
In a spinel structure, the formula is typically \(AB_2O_4\), where:
For an inverse spinel, the \(A^{2+}\) ions occupy half of the octahedral sites while the \(B^{3+}\) ions are split between the remaining octahedral and all tetrahedral sites. Thus, an inverse spinel can be described as \((B^{3+})[A^{2+}B^{3+}]O_4\), with the square brackets denoting the octahedral sites.
Let's analyze the given options:
Thus, the correct answer for an inverse spinel configuration is: \(Ni(II)\) and \(Ga(III)\). This configuration allows \(Ni^{2+}\) to be in the octahedral sites and \(Ga^{3+}\) to distribute across both available site types, conforming with the inverse spinel structure.
The band structure given below represents a
