INTENSE VISIBLE-LIGHT EMISSION FROM SR3AL2O6-EU,DY

The triboluminescence intensity from stress-activated Sr3Al2O6:Eu, Dy (SAO- ED) was so strong that we could see it with the naked eye in the atmosphere. The luminescence integrated intensity was about five hund red times as high as that of crystal sugar. We think that the light em ission is due to the movement of dislocations and the 4f(7)-4f(6)5d tr ansition in the doped Eu2+ ions from the analysis of the emitted light . Furthermore, we have discovered the new phenomenon that the luminesc ence intensity of the SAO- ED is recovered by the irradiation of ultra violet light. (C) 1998 American Institute of Physics. [S0003-6951(98)0 2747-8].