English

Order and disorder around Cr$^{3+}$ in chromium doped persistent luminescence AB$_2$O$_4$ spinels

Materials Science 2015-06-30 v1

Abstract

X-ray absorption near edge structure (XANES) spectroscopy technique is used to better understand the charging and decharging processes of the persistent luminescence in the Cr3+^{3+} doped AB2_2O4_4 spinels (A = Zn, Mg and B = Ga and Al) with low photon energy excitation by visible light. Cr K edge XANES spectra have been simulated for different near neighbour environments around the Cr3+^{3+} recombination centres and compared with the experimental curve. In Cr3+^{3+}:ZnGa2_2O4_4 compound, the Cr3+^{3+} local structure corresponds mostly to that of a normal spinel (\sim70\%), while the rest comprises of distorted octahedral environment arising from cationic site inversion and a contribution from chromium clustering. This local structure is strongly different in Cr3+^{3+}:MgGa2_2O4_4 and Cr3+^{3+}:ZnAl2_2O4_4 where, for both cases, chromium clustering represents the main contribution. The strong correlation between the intensity of persistent luminescence and \% of Cr in clusters leads us to infer that presence of Cr clusters is responsible for decrease of the intensity of the visible light induced persistent luminescence in the Cr3+^{3+} doped AB2_2O4_4 spinels.

Keywords

Cite

@article{arxiv.1503.07979,
  title  = {Order and disorder around Cr$^{3+}$ in chromium doped persistent luminescence AB$_2$O$_4$ spinels},
  author = {Neelima Basavaraju and Kaustubh R. Priolkar and Didier Gourier and Aurélie Bessière and Bruno Viana},
  journal= {arXiv preprint arXiv:1503.07979},
  year   = {2015}
}

Comments

in Phys. Chem. Chem. Phys. (2015)