Study of Eu3+ → Eu2+ reduction in BaAl2O4:Eu prepared in different gas atmospheres

• The effect of different gas atmospheres on the Eu reduction process was studied.
• The Eu reduction was monitored analyzing XANES region at the Eu LIII-edge.
• Hydrogen reducing agent are the most appropriate gas for Eu2+ stabilization.
• Only a part of the Eu ions can be stabilized in the divalent state.
• A model of Eu reduction process is proposed.

The effect of different gas atmospheres such as H2(g), synthetic air, carbon monoxide (CO) and nitrogen (N2) on the Eu3+ → Eu2+ reduction process during the synthesis of Eu-doped BaAl2O4 was studied using synchrotron radiation. The Eu3+ → Eu2+ reduction was monitored analyzing XANES region when the sample are excited at the Eu LIII-edge. The results show that the hydrogen reducing agent are the most appropriate gas for Eu2+ stabilization in BaAl2O4 and that only a part of the Eu ions can be stabilized in the divalent state. A model of Eu reduction process, based on the incorporation of charge compensation defects, is proposed.

Figure optionsDownload as PowerPoint slide