Structural and Luminescent Properties of a Nasicon-Type Phosphate CuI0.5MnII0.25Zr2(PO4)3

The phosphate CuI0.5MnII0.25Zr2(PO4)3 can be obtained at 1000°C by exchange reaction in CuII0.5Zr2(PO4)3. It crystallizes in the rhombohedral system (space group R ) with the parameters ah=8.8352(1) ? and ch=22.254(5) ? in the equivalent hexagonal cell. The structure refined by the Rietveld method is typical of Nasicon-type structure. Mn2+ ions occupy partially the M1 site, while Cu+ ions are distributed over the M1 and M2 sites generated by the space group. This compound exhibits two fluorescences, occurring in the violet and orange regions and assigned respectively to isolated Cu+ and Mn2+ ions. Two other luminescences detected in the blue and green range at low temperature correspond respectively to (Cu2)+ and (Cu+)2 Apairs. Efficient energy transfer Cu+Mn2+ is observed at room temperature strengthening the orange emission of Mn2+ in the M1 site.