Facile synthesis, structure, and properties of Gd2O2Se

Inorganic phosphors based on rare earth elements are commonly used as scintillation materials due to their high chemical and radiation resistance. In this work, we study gadolinium oxyselenide as a new phosphor material. The work describes a facile synthesis method for Gd2O2Se. Single crystal structure of this compound was determined for the first time: sp.gr. P3m1 with a = 3.8911(4) angstrom and c = 6.8829(8) angstrom. Gd2O2Se is stable in the inert atmosphere and melts at 2075 +/- 20 degrees C. This material is also stable when heated in air up to 720 degrees C. with the following oxidation and weight increase. This mass increase can be explained by the oxidation of Se2- to Se4+. Further temperature increase above 952 degrees C leads to a sharp mass loss and the final mass of sample corresponds to full oxidation of Gd2O2Se to gadolinium oxide. The band gap of the material was estimated to be 3.6 eV. Photoluminescence spectrum for Gd2O2Se:Tb3+ shows the characteristic transitions in Tb3+ ion with the most intense green emission that corresponds D-5(4) -> F-7(J) transitions.

Automated summary

This work presents a study on the synthesis and properties of gadolinium oxyselenide as a new phosphor material. The compound's crystal structure, stability, and behavior at different temperatures are discussed.