Optical and structural properties of doped BaBrI and BaClI crystals
arXiv:1703.08926 · doi:10.1016/j.jlumin.2017.07.059
Abstract
The work is necessitated by search for new materials to detect ionizing radiation. The rare-earth ions doped with ternary alkali earth-halide systems are promising scintillators showing high efficiency and energy resolution. Some aspects of crystal growth and data on the structural and luminescence properties of BaBrI and BaClI doped with low concentrations of ions are reported. The crystals are grown by the vertical Bridgman method in sealed quartz ampoule. New crystallography data for BaClI single crystal obtained by single crystal X-ray diffraction method are presented in this paper. Emission, excitation and optical absorption spectra as well as luminescence decay kinetics are studied under excitation by X-ray, vacuum ultraviolet and ultraviolet radiation. The energies of the first 4f-5d transition in and band gap of the crystals have been obtained. We have calculated the electronic band structure of the crystals using density functional theory as implemented in the \latin{Ab Initio}. Calculated band gap energies are in accord with the experimental estimates. The energy of gaps between the occupied Eu 4f level and the valence band top are predicted. In addition, positions of lanthanide energy levels in relation to valence band have been constructed using the chemical shift model.
arXiv comment28 pages, 10 figures
References in corpus (8)
- Quasiparticle band structure based on a generalized Kohn-Sham scheme
- Prediction model of band-gap for AX binary compounds by combination of density functional theory calculations and machine learning techniques
- First-Principles Studies of Luminescence in Ce doped Inorganic Scintillators
- First-principles study of luminescence in Eu-doped inorganic scintillators
- Scintillation properties of pure and Ce-doped SrF crystals
- Instability of some divalent rare earth ions and photochromic effect
- Absolute light yield measurements on SrF and BaF doped with rare earth ions
- Spectroscopy of divalent rare earth ions in fluoride crystals