Journal of Materials Research

Articles

Neutron Rietveld Analysis for Optimized CaMgSi2O6:Eu2+ and its Luminescent Properties

Won Bin Ima1, Yong-Il Kima2, Jong Hyuk Kanga3, Duk Young Jeona3 c1, Ha Kyun Junga4 and Kyeong Youl Junga4

a1 Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea

a2 Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-600, Republic of Korea

a3 Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea

a4 Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong-gu, Daejeon 305-600, Republic of Korea

Abstract

We optimized synthesis conditions of blue-emitting CaMgSi2O6:Eu2+ (CMS:Eu2+) with conventional solid-state reaction and successfully determined structure parameters by Rietveld refinement method with neutron powder diffraction data. The final weighted R-factor Rwp was 6.42% and the goodness-of-fit indicator S (= Rwp/Re) was 1.34. The refined lattice parameters of CMS:Eu2+ were a = 9.7472(3) Å, b = 8.9394(2) Å, and c = 5.2484(1) Å. The β angle was 105.87(1)°. The concentration quenching process was observed, and the critical quenching concentration of Eu2+ in CMS:Eu2+ was about 0.01 mol and critical transfer distance was calculated as 12 Å. With the help of the Rietveld refinement and Dexter theory, the critical transfer distance was also calculated as 27 Å. In addition, the dominant multipolar interaction of CMS:Eu2+ was investigated from the relationship between the emission intensity per activator concentration and activator concentration. The dipole–dipole interaction was a dominant energy transfer mechanism of electric multipolar character of CMS:Eu2+.

(Received February 15 2005)

(Accepted April 07 2005)

(Online publication August 2005)

Key Words:

  • Luminescence;
  • Neutron scattering

Correspondence:

c1 Address all correspondence to this author. e-mail: dyj@kaist.ac.kr

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