Cathodoluminescence in europium doped KCl crystals

Abstract

Spectral cathodoluminescence of KCl:EU2+ (0.2% wt) crystals has been measured at different temperatures. In the 80-300 K temperature range the luminescence consists of three main broad emission bands with maxima around 418, 452, and 619nm. Based on photoluminescence studies the 418nm could be associated with the 4f(6)5d (t(2g))-4f(7) (S-8(7/2)) radiative transition of the Eu2+ ions in the KCl matrix. The band with maximum at 452 nm could be associated with the alpha-center emission as in pure KCl. The 619 nm band has been considered as a part of the luminescence modified by the absorption of the F centers formed during irradiation. The intensity of all these bands versus temperature shows a minimum around 150 K, an indication of a low defect mobility produced with the electron-beam irradiation.