Crystal growth, structures, magnetic and photoluminescent properties of NaLnGeO4 (Ln = Sm, Eu, Gd, Tb)

• NaLnGeO4 (Ln = Sm, Eu, Gd, Tb) have been synthesized and characterized.
• The oxides exhibit a complex three-dimensional crystal structure.
• Magnetic susceptibility data were collected.
• The room temperature photoluminescence was investigated.

Single crystals of NaLnGeO4 (Ln = Sm, Eu, Gd) were grown out of a molten sodium hydroxide flux, and their crystal structures were determined by single crystal X-ray diffraction. The lanthanide containing germanates crystallize in the orthorhombic space group of Pnma, and exhibit a complex three-dimensional structure consisting of corner- or edge-shared LnO6, GeO4, and NaO6 polyhedra. UV–vis diffuse reflectance spectra indicated that the reported oxides are insulating materials with wide band gaps. The magnetic susceptibility data shows paramagnetic behavior. For the NaEuGeO4 and NaTbGeO4 compositions intense room temperature photoluminescence was observed.

Single crystals and powder samples of NaLnGeO4 (Ln = Sm, Eu, Gd, Tb) were prepared via a sodium hydroxide melt and conventional solid-state methods. The three-dimensional crystal structure was determined by single crystal X-ray diffraction. Magnetic susceptibility data were collected and the room temperature photoluminescence was investigated.Figure optionsDownload as PowerPoint slide