Electron irradiation effects on cathodoluminescence in zircon

Cathodoluminescence (CL) measurements of zircon sample with two different geological ages have been conducted to clarify the polarization effect of different types of luminescence centers and the effects of electron-irradiation on CL. Polarization of CL has been confirmed in the emissions related to both defect and impurity centers in zircon. Prolonged exposure of electron irradiation reduces the CL intensities of broad bands related to intrinsic defect centers in the blue region and those of narrow bands attributed to Dy³⁺ activator, whereas CL intensity of the broad bands attributed to metamictization in the yellow region increases with prolonged irradiation. Therefore, electron irradiation has a different effect on the emission mechanisms of defect centers observed in the blue and yellow regions.