Photoluminescence of divalent cobalt ions in tetrahedral sites of zinc orthotitanate

• Published in: Journal of alloys and compounds 2017-10, Vol.720, p.417-422
• Main Authors: Espinoza, V.A.A., López, A., Neumann, R., Sosman, L.P., Pedro, S.S.
• Format: Article
• Language: English
• Subjects: A. Insulators; C. X-ray diffraction; Carbon dioxide; Chemical synthesis; Cobalt; D. Luminescence; Diffraction; Electron spin; Excitation spectra; Near infrared radiation; Photoluminescence; Polycrystals; Solid state; Spectral emissivity; Temperature; Zinc
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.05.188

Zinc orthotitanate (Zn2TiO4) polycrystalline samples doped with Co2+ ions were synthesized by solid state reaction and investigated by X-ray diffraction and photoluminescence spectroscopy at room temperature. Two bands were detected in the photoluminescence spectrum in the near infrared range: the most intense, centered at 714 nm assigned to the T14(P4)→A24(F4) and a less intense band, identified as T14(P4)→T24(F4), both generated from spin-allowed electronic transitions. Photoluminescence excitation spectrum at 714 nm exhibits typical transitions of Co2+ in tetrahedral coordination. From the transitions observed in emission and excitation spectra and using the Tanabe-Sugano theory, the crystal field parameter Dq and Racah parameters B and C were obtained. The intense and broad emission band in the near infrared makes this system a material with high potential for use as tunable media. •Photoluminescent properties of the Zn2TiO4:Co2+ are reported.•The material has a broad band in the infrared range, assigned to Co2+ transitions.•The calculated crystal field parameters indicate a tetrahedral environment.•Their features make this system a material with potential for use as tunable media.