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Nd 3+ :Cs 2 NaGdCl 6 and Nd 3+ , Yb 3+ :Cs 2 NaGdCl 6 polycrystalline powder samples were prepared by Morss method E. Under 785 nm semiconductor laser pumping, the upconversion luminescence of Nd 3+ ions in Cs 2 NaGdCl 6 was investigated at room temperature, and three upconversion emissions near 538 nm (Green), 603 nm (Orange), and 675 nm (Red) were observed and assigned to 4 G 7/2 → 4 I 9/2 , ( 4 G 7/2 → 4 I 11/2 ; 4 G 5/2 → 4 I 9/2 ), and ( 4 G 7/2 → 4 I 13/2 ; 4 G 5/2 → 4 I 11/2 ), respectively. The dependences of these upconverted emissions on laser power and Nd 3+ ion concentration were investigated, to explore the upconversion mechanism. The effect of doping Yb 3+ ions on the upconversion luminescence of Nd 3+ in Cs 2 NaGdCl 6 was also studied under 785 nm laser excitation. The energy transfer processes were discussed as the possible mechanism for the above upconversion emissions. |
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