Mn K-edge XAS analyses of Zn2-xMnxSiO4 phosphors

Green-emission intensity of a Zn2-xMnxSiO4 phosphors, which is a potential candidate as a green component in PDP device, significantly increases provided that the compound is additionally heat treated at 900 .deg. C after solid state reaction at 1300 .deg. C. In order to verify origin of such an intensity enhancement after the additional heat treatment in association with the electronic and local structural change at around Mn ions, the Mn K-edge X-ray absorption spectra were recorded. From the analyses of the preedge peak corresponding to 1s→3d bound state transition and XANES spectrum, it is known that most Mn ions are in +2 oxidation state and substitute Zn ion site regardless of the thermal treatment. In addition, EXAFS analyses revealed that Mn ions formed MnO4 tetrahedra with Mn-O bond length shortened by 0.01 A and with reduced Debye-Waller factor in the thermally treated sample