Crystal Field Splitting in Potassium Perchromate

Measurements of the diffuse reflectance spectrum of K3CrO8 and its dilutions in CaF2 essentially support the transmission results of Swalen and Ibers. Peaks observed at 2.00 and 2.53 eV are attributed to d—d transitions on the Cr5+ ion, others at 3.35 and 5.00 eV to charge transfer. A crystal field analysis yields a Dq value of 0.41 eV for the Cr5+ ion, a result consistent with that obtained from the spectrum of the hypochromate ion, 0.45 eV.