Spectroscopy of Mn $O_{4}^{3 -}$ in Calcium Halophosphates

A study has been made of the optical absorption and fluorescence of the compounds

{Ca}_{2}

O_{4}

Cl (spodiosite) and

{Ca}_{5}

{(P O_{4})}_{3}

Cl (apatite) doped with

{Mn}^{5 +}

. The

{Mn}^{5 +}

ion has the electronic configuration

3 d^{2}

and it substitutes for the phosphorous ion, producing the hypomanganate ion, Mn

O_{4}^{3 -}

. The

{Mn}^{5 +}

ion is in a field with a symmetry that is approximately tetrahedral (

T_{d}

) but the lower symmetry components are strong enough to split the energy levels by several hundred

{cm}^{- 1}

. The prominent features of the absorption spectra are two sharp lines between 8300 and 8800

{cm}^{- 1}

, two strong broad bands between 12 000 and 20 000

{cm}^{- 1}

, a third strong band near 31 000

{cm}^{- 1}

, and a complex structure between 21 000 and 25 000

{cm}^{- 1}

. We believe that the sharp lines are due to transitions (

{}^{3}A_{2} \to {}^{1}E

) within the ground-state (

e^{2}

) configuration, while the three strong bands (oscillator strengths from 3×

10^{- 3}

to 3×

10^{- 2}

) are due to the three lowest-energy allowed one-electron transitions,

e^{2} : {}^{3}A_{2} \to e t_{2} : {}^{3}T_{1}

This publication has 12 references indexed in Scilit:

Spectroscopy of MnO43−in Calcium Halophosphates