Structural influence on photochromic behaviors of Eu2+-doped glaserite-type silicates

Ba(2.98-x)SrxEu(0.02)MgSi(2)O(8) (x <= 0.365) exhibited emission-color change when exposed to the light from a Xe arclamp. Blue emission observed from the above phosphors turned purple after the photostimulation because of 608-nm emission centers arising. The degree of the spectral change monotonically decreased with increasing Srreplacement x, and became undetectable when x exceeded 0.490. This x value coincided with that dividing the structural symmetry between P (3) over bar (Z = 3) and P (3) over bar m1 (Z = 1). This coincidence indicates that structural distortion caused by B-site Ba2+ ions contributes to the photostimulated emission-color change of the Eu2+-doped glaserite- type alkali-earth magnesium silicates.