Systematic Study on the Luminescent Properties, Thermal Stability, and Magnetic Behavior of GdOF: RE 3+ (RE = Eu, Yb, and Er) Red Phosphors with Various Morphologies.

In this work, GdOF:RE 3+ (RE = Eu, Yb, and Er) phosphors with high thermally stable luminescence were reported, which were synthesized by an ionic liquid-assisted two-phase system and subsequent calcination technique for the first time. Nanodisks, nanorod aggregates, nanoneedles, and stubby nanorods were obtained by simply regulating the pH value. The luminescent properties of precursors and products were discussed in detail. By carefully adjusting the calcination temperature and the pH value of the initial system, pure red emission was achieved in both GdOF:Eu 3+ and GdOF:Yb 3+ , Er 3+ phosphors. The reason for distinct luminescent properties of different products was discussed from various perspectives. Moreover, the temperature-dependent spectra were measured and the GdOF:Eu 3+ and GdOF:Yb 3+ , Er 3+ products both exhibited outstanding thermal stability. In addition, the as-prepared nanomaterials presented paramagnetic properties, indicating their potential application in both field-emission displays and magnetic resonance imaging technology.