Synthesis and structural characterization of Eu-doped [Zn.sub.7][Sb.sub.2][O.sub.12]

• Published in: Journal of materials science 2010-08, Vol.45 (15), p.4216
• Main Authors: Silva, A.C.S, Souza, G.G, Nobre, M.A.L, Pires, A.M
• Format: Article
• Language: English
• Subjects: Analysis; Chemical properties; Rare earth metals; Solid solutions; Spinel group
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-010-4516-2

In addition to the lanthanide series elements, Europium is one of the chemical elements of greatest interest for the development of species with oxidation state +3 (III), which leads to interesting electronic transitions. In a general sense, their emission spectrum lines are narrow and sensitive to effects of the ligand field around metallic ions. This property allows the use of Eu(III) as a structural probe. In this work, samples of semiconductor [Zn.sub.7][Sb.sub.2][O.sub.12] and of solid solutions based on isoelectronically Eu(III)doped [Zn.sub.7][Sb.sub.2][O.sub.12] with stoichiometry [Zn.sub.7- 3x][Eu.sub.2x][Sb.sub.2][O.sub.12] were prepared. Both [Zn.sub.7][Sb.sub.2][O.sub.12] and [Zn.sub.7- 3x][Eu.sub.2x][Sb.sub.2][O.sub.12] were synthesized via a chemical route using Pechini's method and characterized by Fourier transform infrared absorption vibrational spectroscopy (FTIR) and photoluminescence spectroscopy. In order to perform further spectral analyses, each spectrum was adjusted using a set of Gaussian functions. The FTIR spectrum analysis showed a slight band shift of the vibration mode assigned to the Sb-O bonding ascribed to the [SbO6] octahedron vibration. The theoretical fitting of the luminescence curves showed a broadening of the most intense emission peaks related to the transition Eu(III) [sup.5][D.sub.0] → [sup.7][F.sub.2]. As a whole, the results suggest that a less symmetric Eu(III) site occupation in inverse spinel structure may occur in sites close to the antimony octahedron, involving, however, non-substitutional site occupation.