Fe3+ luminescence centres in aluminium fluoride

Abstract A new phosphor, γ-AlF 3 :Fe 3+ , is reported in which octahedrally coordinated Fe 3+ gives rise to a broad emission band with a peak at 735 nm. From the data obtained from the excitation spectrum of this emission and that of γ-AlF 3 :Cr 3+ it is shown that Δ(10Dq) values are slightly smaller and Racah parameters larger in the fluoride than in comparable oxide structures; the Fe 3+ emission is consequently at a much shorter wavelength than is expected for oxide structures in which the Fe 3+ ion is octahedrally coordinated.