On the mechanism of persistent up-conversion luminescence in the ZrO2:Yb3+,Er3+ nanomaterials
The up-converting ZrO2:Yb3+,E3+ nanomaterials were prepared with the combustion and sal-gel methods. The structure of the materials was cubic except for the minor monoclinic and tetragonal impurities associated with the use of the sal-gel method. The XANES results revealed only the trivalent form for both the Yb and Er dopants. The distance distributions calculated from EXAFS confirm that Er3+ and
