Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a ...Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a monoclinic structre belonging to the P21/m space group. The unit cell volumes of the Gdo.9 xLaxEuo.OOH crystals increased with increasing x, whereas those of Gdo.9-xYxEUo.lOOH decreased with increasing x. The Commission Internationale de IEclairage （CIE） chromaticity coordinates of Gdo.9 xRxEUo.lOOH （R=Y, La） crystals were located in the red region and were nearly constant over the range ofx values considered. The fluorescence quantum yield Dr monotonically decreased with increasing x regardless of the ionic radii of the substitute ions. The fact that the Dr value of Lao.9EuoAOOH was greater than that of Gdo.gEUo.lOOH indicated that the observed decrease in the values of the Gdo.9-,LaxEuo.1OOH crystals up to x=0.3 could not be attributed to an increase in the distance between Eu3＋ ions or to a decrease in the Gd3＋ content. The decrease might be due to an increase of killer centers introduced by elemental substitutions with the larger ion.展开更多
基金supported by Japan Society for the Promotion of Science(JSPS)KAKENHI Grants(2156069624560827)
文摘Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a monoclinic structre belonging to the P21/m space group. The unit cell volumes of the Gdo.9 xLaxEuo.OOH crystals increased with increasing x, whereas those of Gdo.9-xYxEUo.lOOH decreased with increasing x. The Commission Internationale de IEclairage （CIE） chromaticity coordinates of Gdo.9 xRxEUo.lOOH （R=Y, La） crystals were located in the red region and were nearly constant over the range ofx values considered. The fluorescence quantum yield Dr monotonically decreased with increasing x regardless of the ionic radii of the substitute ions. The fact that the Dr value of Lao.9EuoAOOH was greater than that of Gdo.gEUo.lOOH indicated that the observed decrease in the values of the Gdo.9-,LaxEuo.1OOH crystals up to x=0.3 could not be attributed to an increase in the distance between Eu3＋ ions or to a decrease in the Gd3＋ content. The decrease might be due to an increase of killer centers introduced by elemental substitutions with the larger ion.
