Photoluminescence, optical absorption and XRD studies on X-ray irradiated terbium doped KBr crystals

This paper reports the optical absorption, photoluminescence (PL), XRD, SEM studies made on KBr:Tb3+ crystals. The integrated light intensity is enhanced by about two orders of magnitude as compared to the undoped samples in spite of some OH- present in the samples. PL of these crystals exhibits characteristic Tb3+ emissions due to transitions from the 5D3 to 5D4 levels to various levels of the 7F septet on F-bleaching X-ray irradiated crystals Z3 centers are observed. The bands observed in the emission spectra of Tb3+ doped KBr are found to be shifted to higher wavelength. The stokes-shift of KBr:Tb3+ is determined and it is found to have a large value. The XRD studies have been made to determine the crystalline structure of KBr and KBr:Tb3+ and also the Miller indices. The SEM studies made reveal the presence of microcrystalline structure.