Article ID Journal Published Year Pages File Type
1616147 Journal of Alloys and Compounds 2012 5 Pages PDF
Abstract

Nd3+ doped MgAl2O4 spinel nanocrystals have been prepared by the sol–gel method. Their size decreases from 12 to 7 nm with increasing Nd3+ concentration from 0.1 to 5%, respectively. Some crystal field components of the Nd3+ energy levels in MgAl2O4 spinel were found from the 300 K reflectance absorption and the 77 K emission spectra. The 4F3/2 → 4I9/2 transition dominates in the emission spectra and accordingly spectroscopic-quality parameter (SQP) is equal to 3.3 for all samples. Decay time of the emission from the 4F3/2 level in MgAl2O4:Nd3+ (0.1%) nanocrystals is equal to 90 μs, and decreases with increasing neodymium concentration due to very efficient cross-relaxations. The slope of cross-relaxation rate is close to 2 which indicates fast donor–donor transfer.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of the nanocrystalline powders of magnesium aluminate (MgAl2O4) spinel doped with neodymium(III) ions by modified Pechini synthesis. ► Spectroscopic-quality parameter values are above 3 for all samples. ► The 4F3/2 → 4I9/2 transition of neodymium dominates in emission spectra in spinel lattice. ► Very effective cross relaxation rate indicates rapid donor–donor transfer.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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