Effect of gamma-ray irradiation on structures and luminescent properties of nanocrystalline MSO4 : xEu(3+) (M = Ca, Sr, Ba; x=0.001-0.005)

A series of nanocrystalline rare earth doped alkaline earth sulphates, MSO4 :xEu(3+) (M = Ca, Sr, Ba; x = 0.001-0.005), have been prepared by co-precip itation method, Their crystal structures and luminescent properties with an d without gamma-ray irradiation are compared. It was found that their cryst al structures have not changed, but their lattice parameters with irradiati on become smaller than those without irradiation. On the other hand, the ch aracteristic emissions of both Eu3+ and Eu2+ are observed in the same nanoc rystals with gamma-irradiation. The differences in their crystal structures and luminescent properties are also discussed, (C) 1999 Elsevier Science L td. All rights reserved.