Al3+ environments in nanostructured ZnAl2O4 and their effects on the luminescence properties.
Single-phase zinc aluminate (ZnAl2O4) with the spinel structure was successfully obtained by the Pechini method at different calcining temperatures for 4 hours. The nanoparticles are highly crystalline with no impurities related to ZnO or Al2O3 residues. The microstructural environment of aluminium ions changes with heat treatment temperature, as observed by Fourier transform infrared spectroscopy. The spinel structure might present two different AlO6 sites as evidenced by 27Al solid-state magic-angle-spinning nuclear magnetic resonance spectra. Some AlO4 sites were also detected for samples calcined at a temperature lower than 900 degrees C. The photoluminescence spectra show that the emission can be tuned depending on the calcining temperature. This effect was discussed on the basis of symmetry and oxygen vacancies.
da Silva
Alison A
AA
São Paulo State University-UNESP Institute of Chemistry, Luminescent Materials Laboratory-LML, P.O. Box 355, 14801-970 Araraquara/SP Brazil.
Gonçalves
Agnaldo S
AS
Davolos
Marian R
MR
Santagneli
Silvia H
SH
D000535:Aluminum / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry*
D046911:Macromolecular Substances; D017967:Zinc Compounds; D000535:Aluminum