Remarkable Differences in Photoluminescence Properties Between BaF2:Eu3+ Microrods and Nanorods

The preparation process and photoluminescent properties of one-dimensional BaF2:Eu3+ nanorods (NRs) and microrods (MRs) were investigated. The results indicate that the samples were NRs with uniform diameters in the range of 30-50 nm, and lengths in the range of 1.2-3 mu m when cooled to room temperature naturally. However, the samples were MRs with length of 1.5-3.0 mu m and outer diameters of 200-250 nm when cooled to room temperature immediately. Furthermore, the relative intensity of D-5(0) -> F-7(2) depended on the two structures obtained under different temperatures. This work demonstrates that a MRs may be more favorable than NRs for photoluminescence.