Luminescent materials nowadays find use among a variety of different applications, thus attracting a lot of attention for studying such compounds. Many such materials can be obtained by doping a certain matrix with lanthanide ions. This work concentrates on NaAlGeO4 doped with europium (III) ions, as properties of such compound are relatively unknown.
Samples (Na1-xAlGe1-0.5xO4Eux) were obtained using solid-state synthesis. Stoichiometric amounts of sodium carbonate, aluminum oxide, germanium (IV) oxide and europium (III) oxide were weighed, mixed in agate mortar and sintered in 1000 °C for 6 hours.
The samples were firstly analyzed by X-ray diffractometer. Using the obtained X-ray diffraction results, it was concluded that all of the samples are single-phased. The aforementioned data was also used to refine the existing NaAlGeO4 unit cell using the Rietveld method. It was determined that the occupancy of europium sites in the crystal cell directly correlates to the bulk concentration of europium during the solid-state synthesis. Also, samples with more europium tended to have a bigger unit cell.
The luminescent properties of the specimens were investigated by photoluminescence spectroscopy. Samples with higher europium concentrations showed strongest emission when excited by light wavelength of 392.5 nm. The highest emission peaks observed were at 610 nm and 702.5 nm.