Multifunctional ScF3:Ln3+ (Ln = Tb, Eu, Yb, Er, Tm and Ho) nano/microcrystals: hydrothermal/solvothermal synthesis, electronic structure, magnetism and tunable luminescence properties.

A facile, hydrothermal/solvothermal route has been developed to synthesize a series of multifunctional lanthanide ion (Tb(3+), Eu(3+), Yb(3+), Tm(3+), Er(3+) and Ho(3+))-activated ScF3 nanocrystals. The morphology and size of ScF3 can be tuned in a controlled manner by altering the additives and volume ratios of H2O : EtOH in the initial solution. Under ultraviolet (UV), vacuum ultraviolet (VUV) or low-voltage electron-beam excitation, the as-obtained Tb(3+), Eu(3+) codoped ScF3 product exhibits multicolor photoluminescence (PL) and cathodoluminescence (CL), and possible luminescence mechanisms are discussed. Moreover, under 980 nm excitation, upconversion (UC) emissions have been achieved in Yb(3+)-Er(3+), Yb(3+)-Tm(3+), and Yb(3+)-Ho(3+) codoped ScF3. Ferromagnetic property of ScF3 is detected due to the nanocrystal defects. The results obtained indicate that the lanthanide ion-doped ScF3 nanocrystals exhibit multicolor UV/VUV PL, CL, and UC luminescence as well as ferromagnetic properties. Thus, they may have potential applications in PL areas, field emission display devices, bioseparation and magnetic resonance imaging.