Spherical Microstructures of Lu 2 O 3 :Ln 3+ (Ln=Tm, Dy, Tb, Eu): Rapid Microwave‐Assisted Synthesis, Energy Transfer, and Multicolor Emission

Abstract Lu 2 O 3 :Ln 3+ (Ln=Tm, Dy, Tb, Eu) microspheres have been synthesized via a rapid microwave route followed by annealing process. Diverse morphologies of samples can be easily realized by changing the volume ratio of H 2 O/EtOH. The samples were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), fourier transform infrared spectroscopy (FT‐IR), thermogravimetry analysis (TGA). Under the excitation of UV light, Lu 2 O 3 :Ln 3+ exhibited the characteristic transitions of Ln 3+ , and green (Tb 3+ ), blue (Tm 3+ ), red (Eu 3+ ), yellow (Dy 3+ ) light can be obtained. Under 360 nm irradiation ( 1 D 2 ‐ 3 F 4 transition of Tm 3+ ), both characteristic transitions of Tm 3+ and Dy 3+ can be observed in Lu 2 O 3 :1%Tm 3+ , x %Dy 3+ samples. Furthermore, the critical distance between Tm 3+ and Dy 3+ was calculated, and the energy transfer process from Tm 3+ to Dy 3+ was dipole‐dipole interaction. This synthetic method may be useful for preparing other inorganic materials with multi‐color emitting.