Structural, mechanical, thermal and optical properties of NaCl:Ce3+ single crystals grown in large size by the Czochralski method

Abstract

NaCl:XCe3+ crystals (with X = 0.0 (pure NaCl), 0.001, 0.003, 0.005, 0.006, 0.008 and 0.01) have been grown in large size by using the resistance heating Czochralski method and characterized structurally, mechanically, thermally and optically by carrying out X-ray diffraction (XRD), micro-hardness, thermal stress, optical absorption, photoluminescence (PL) emission, photoluminescence excitation (PLE), thermo-luminescence (TL) and decay time measurements. XRD analysis indicates compression of the NaCl host lattice due to incorporation of Ce3+ ions. Hardness analysis has confirmed that Ce3+ doping improves the hardness of NaCl crystal in proportion with the Ce3+ concentration. Thermal stress analysis indicates that the grown crystals are of high quality. Optical absorption spectra obtained for the Ce3+ doped crystals have illustrated the presence of four peaks at 203, 215, 223, 303 and 414 nm. The Ce3+ doping has been found to influence the excitation and emission peaks due to Ce3+ (4f↔5d) transitions. The TL glow curves obtained show one sharp peak located at about 145 °C; the peak at 120 °C becomes prominent on bleaching with F-light after irradiation. The luminescence decay time has been found to gradually decrease with the increase in Ce3+ concentration. The PL and TL performances have been found to be maximum for the NaCl:0.008Ce3+ crystal. The present study indicates that the NaCl:Ce3+ crystals grown can be considered as promising materials for their use in dosimetry and scintillation applications.