Light absorption of CrIII in two host lattices of pyroxene and spinel type

The light absorption of Cr³⁺ – doped diopside CaMgSi₂O₆ and spinel ZnGaAlO₄ was measured spectrophotometrically. Two absorption bands corresponding to the electron transition: ⁴A_2g → ⁴T_2g (low frequency band) and ⁴A_2g → ⁴T_1g (high frequency band) were obtained. Generally, the value of the estimated ligand field parameters Δ and B showed that the Cr? O bond in the studied two structures is of different character.