The Effect of Rapid Cooling on Divalent Manganese Ions in Calcium Fluoro-Chlorophosphate Phosphors

Abstract

Quenching experiments were performed on manganese‐activated calcium fluoro‐chlorophosphate phosphors. Changes in the optical properties of the manganese ions due to quenching were studied in order to explain the manganese fluorescent envelope shift in quenched phosphors reported by other workers. We find that quenching causes a change in the nearest halogen neighbors of manganese ions located on the so‐called “Ca(II)” positions. In slowly cooled phosphors these ions have mostly chlorine ions as nearest neighbors while in the quenched phosphors many of the chlorine ions are replaced with fluorine. It is shown that this redistribution will produce a shift in the manganese fluorescence envelope equal in magnitude to that experimentally observed.

A Review of Depreciative Color Center Phenomena in Lamp Phosphors

“…This causes a slight expansion of the lattice with the C1 ions displaced slightly above and below the would-be F position. If at least 36% of the halogens in the mixed chlorofluorophosphate are fluorines, then the halophosphate remains at all temperatures in the hexagonal apatite structure (18).…”