Luminescent properties of stabled hexagonal phase Sr1−xBaxAl2O4:Eu2+ (x=0.37–0.70)

✍ Scribed by Qiaoli Wu; Zhen Liu; Huan Jiao

• Book ID: 103887352
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 313 KB
• Volume: 404
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2009.05.011

✦ Synopsis

Stabled hexagonal phase Sr 1Àx Ba x Al 2 O 4 :Eu 2+ (x ¼ 0.37-0.70) was prepared by solid-state method. Result revealed that the structure behavior of the SrAl 2 O 4 :Eu 2+ calcined at 1350 1C in a reducing atmosphere for 5 h strongly depended on the Ba 2+ concentration. With increasing Ba 2+ concentration, a characteristic hexagonal phase can be observed. When 37-70% of the strontium is replaced by barium, the structure of the prepared sample is pure hexagonal. Photoluminescence and excitation spectra of the samples with different x and doped with 2% Eu 2+ were investigated. Changes in the emission spectra were observed in the two different phases. The green emission at 505 nm from Eu 2+ was found to be quite strong in the hexagonal phase. The intensity and peak position of the green luminescence from Eu 2+ changed with increasing content of Ba 2+ . The strongest green emission was obtained from Sr 0.61 Ba 0.37 Al 2 O 4 :Eu 2+ . The decay characteristics of Sr 1Àx Ba x Al 2 O 4 :Eu 2+ (x ¼ 0.37-0.70) showed that the life times also varied with the value of x. Furthermore, the emission colors and decay times varying with x could be ascribed to the variation of crystal lattice.