Electronic States of Mn2+-Activated Phosphors.

The electronic states of Mn2+ are derived from excitation spectra for five green‐emitting phosphors: (i) , (ii) , (iii) , (iv) , and (v) . Only is found to give a spectrum consistent with octahedral (or tetrahedral) symmetry of Mn2+; the other four phosphors show spectra typical of Mn2+ in symmetry lower than octahedral. Solution of the Tanabe‐Sugano energy matrices using the levels as input gave Racah parameters of and .