The emission and excitation spectra of Fe-doped Zn2SiO4 (willemite) crystals were measured at temperatures ranging from 10 to 298 K. The luminescence consists of two contributions, both of broadband type: an emission due to the 4T1 (4G) → 6A1 (6S) interconfigurational transition of the d5 Fe3+ ions in sites having approximate tetrahedral coordination and a second emission probably due to lattice defects induced by the requirement of charge compensation. The excitation spectrum of Fe3+ has been assigned on the basis of the ligand field theory, and the energies of the bands have been fitted with the following values of the ligand field parameters: Dq = 743 cm-1, B = 535 cm-1, and C = 3155 cm-1. From these data, it is reasonable to suppose that the Fe3+ ions responsible for the emission are located at the Si4+ distorted tetrahedral sites. © 1995 Academic Press.
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