Structural and photoluminescent properties of nanosized BaMgAl ₁₀ O ₁₇ :Eu ²⁺ blue-emitting phosphors prepared by sol-gel method

Abstract

We report on the photoluminescent properties of Ba 0.9 Eu 0.1 MgAl 10 O 17 (BAM) phosphors in correlation with the host crystalline structures. The phosphors were synthesized by citrate sol-gel process, followed by a sintering and a reduction step, both at elevated temperatures. We found that the phosphors were amorphous when sintered at temperatures below 900 °C. At 1000 °C, the crystalline structure was mainly that of BaAl 2 O 4 phase. The BaMgAl 10 O 17 phase appeared at 1100 °C, and became dominant with increasing temperature. At 1300 °C, the BaAl 2 O 4 phase almost disappeared, and only BaMgAl 10 O 17 features were found. The luminescent characteristics of the phosphors were closely related to the structures of the host lattice. Under the same reduction conditions, the phosphors sintered at 1000 °C showed the emission of both Eu 3+ and Eu 2+ . For the phosphors sintered at higher temperatures, the main features were originated from the emission of Eu 2+ . We additionally observed the increase of emission intensity and the broadening of emission spectra with increasing reduction temperature.