Luminescence studies of zinc borates activated with different concentrations of Ce and La under x-ray and electron excitation

Abstract

Several ZnBO powder samples having dopants concentrations of 0.1, 0.01, 0.04 wt% Ce and La were prepared using the nitric acid method via the starting oxides. Several complementary methods such as powder X-ray diffraction (XRD), thermal analyses environmental scanning electron microscopy (ESEM), Radioluminescence (RL) and Cathodoluminescence (CL) techniques were used. Unique luminescence properties of Ce doped ZnBO powder samples are reported for the first time. A new luminescence bands appearing in red part of the spectrum and having all the characteristics of Ce were obtained from RL results. Changing the Ce and La concentration of 0.01–0.1 wt% leads to an increase in RL and CL intensities of Ce and La ions and also CL emission spectra of ZnBO show gradual shift towards longer wavelength. When we compare the luminescence intensity of the samples it is seen that Ce doped ZnBO has the highest intense whereas La doped ZnBO has the lowest one. However, emission spectra of both Ce and La doped samples kept unchanged.