Luminescent and structural properties of (Sr(1-x),Ba(x))3MgSi2O8:Eu2+: effects of Ba content on the Eu2+ site preference for thermal stability.
A blue-color-emitting phosphor, (Sr(1-x),Ba(x))(3)MgSi(2)O(8):Eu(2+) (SB(x)MS:Eu(2+)), with various Ba contents, was synthesized, and its thermal stability was evaluated. Depending upon the Ba content, the dominant emission wavelength of the SB(x)MS:Eu(2+) phosphor could be tuned, and good photoluminescence (PL) properties were obtained under an excitation by a 147 nm source. The PL behavior showed that the thermal stability of SB(x)MS:Eu(2+) baked at 500 degrees C was dependent upon the Ba content. On the basis of the results of electron spin resonance on Eu(2+) and Rietveld refinement against neutron powder diffraction data of the phosphor, it was found that the improved thermal stability of SB(x)MS:Eu(2+) could be ascribed to Eu(2+) occupying preferred Sr sites among three possible locations depending upon the amount of Ba substitution. It is also inferred from this observation that the average interatomic distances between Eu(2+) and O (d(Eu-O)) of the different Sr sites may play an important role in the thermal stability of the phosphor.
Im
Won Bin
WB
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea. imwonbin@mrl.ucsb.edu
Kim
Yong-Il
YI
Yoo
Hyoung Sun
HS
Jeon
Duk Young
DY