Luminescence properties of samarium-doped SiO2-Na2SO4 composite

摘要: The comprehensive structural and luminescence study of Sm-doped SiO2-Na2SO4 composite materials are reported. The samples were synthesized by melt-mixing mixture of Na2SO4 and SmF3 into the SiO2 matrix at 1050 C for 30 min. X-ray di raction (XRD) pattern shows the characteristic structure of the SiO2 and addition of 20% Na2SO4:Sm has no e ect on the basic crystal structure of the SiO2. Scanning electron microscopy (SEM) shows the clear di erence in morphological structure between the composite and host SiO2. From photoexcitation (PE) spectra of the as-synthesized composite, the highest excitation e ciency was observed at 402 nm. The photoluminescence (PL) spectra of as-synthesized composite phosphors obtained under 402 nm excitation consist of five narrow emission bands with peaks at 563, 598, 644, 704 and 784 nm. These are assigned to the 4G5=2 ! 6HJ (J=5/2, 7/2, 9/2, 11/2 and 13/2, respectively) transitions within 4f5 electronic configuration of Sm3+. Highest luminescence intensity was observed with SiO2-10%Na2SO4:Sm.