Ultrafast synthesis and luminescence properties of rare earth orthoniobates RENbO(RE = La, Eu, Gd, Yb, Lu).

Rare earth orthoniobates (RENbO) are one kind of important functional materials due to its applications in solid-state phosphors, thermal barrier coatings, and microwave dielectric ceramics. The synthesis of rare earth niobates often needs high reaction temperatures (1300 °C-1700 °C) and long processing times (from hours to tens of hours) in solid-state reactions, which can increase the study time of the relationship between structure and properties. In this work, we used ultrafast high-temperature sintering method to synthesize RENbO(RE = La, Eu, Gd, Yb, Lu), and found specific structure and properties in these materials obtained with specific synthetic techniques. Based on the electronegativity scale, the charge transfer energy of lanthanide ions in the YNbOcrystal was calculated. The rapid synthesis of RENbOin a vacuum atmosphere generated more oxygen vacancies, and the structures of [REO] and [NbO] were distorted. The shortening of the fluorescence lifetime of LaNbOand EuNbOwas related to the formation of self-trapped excitons facilitated by lattice distortion. The emission peak of LuNbOat about 530 nm is attributed to the oxygen vacancy in the niobate group. The reported synthetic methods can provide a fast materials screening route for high melting point inorganic materials.