60ZnCl(2)-20KCl-20BaCl(2)-xTbCl(3) glasses (x = 0.10, 0.25, 0.50, 0.75, 1.00, and 1.25) were prepared by melt-quenching method, and Tb3+ fluorescence properties were investigated under 355 nm excitation. Regardless of x values, the electrons that were relaxed from the D-5(3) to D-5(4) level of Tb3+ ions by the multiphonon relaxation, were repressed to 28% of all the excited electrons because the ZnCl2-based glass had much lower phonon energy than oxide glasses. For 0 < x <= 0.34, the cross relaxation, (D-5(3) -> D-5(4)) -> ((7)Fo <- F-7(6)), was repressed, and consequently 72% and 28% of all the excited electrons were radiatively relaxed by the D-5(3) -> F-7(J) (J = 6, 5, 4, 3, and 2) and D-5(4) -> F-7(J) (J = 6, 5, 4, and 3) transitions, respectively. The lifetimes of the D-5(3) and D-5(4) initial levels were obtained to be 1.1 and 2.1 ms, respectively. (C) 2013 Elsevier Ltd. All rights reserved.