Structure and scintillation properties of Ce3+-activated Cs2NaLaCl6, Cs3LaCl6, Cs2NaLaBr6, Cs3LaBr6, Cs2NaLaI6 and Cs3LaI6

• Published in: Journal of luminescence 2014-05, Vol.149, p.374-384
• Main Authors: Gundiah, G., Brennan, K., Yan, Z., Samulon, E.C., Wu, G., Bizarri, G.A., Derenzo, S.E., Bourret-Courchesne, E.D.
• Format: Article
• Language: English
• Subjects: Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Elpasolite; Exact sciences and technology; Gamma-ray detector; Materials science; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Scintillator; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Treatment of materials and its effects on microstructure and properties
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2013.09.057

A systematic study of the structure and scintillation properties of La elpasolites and related compositions with the formula Cs2ALa1−yCeyX6 (where A=Cs, Na; X=Cl, Br, I) is reported. The compounds were determined to crystallize in a variety of crystal structures. Two of the compounds studied are cubic and their structures match a prediction derived from a composition-related tolerance factor. The cubic structure was not obtained with the iodides. Upon optical and X-ray excitation, the samples show the characteristic Ce3+ emission. Depending on the host, the optimal Ce concentration varied between 0.1 and 15%. The luminosity and energy resolution were measured on 4 single crystals with the following results: Cs2NaLaCl6:4% Ce luminosity of 26,400ph/MeV, energy resolution 4.4%; Cs3LaCl6:8% Ce luminosity of 16,000ph/MeV, energy resolution 8.6%; Cs2NaLaBr6:4% Ce luminosity of 46,000ph/MeV, energy resolution 3.9%; Cs3LaBr6:15% Ce luminosity of 32,500ph/MeV, energy resolution 4.9%. Single crystals of the iodide analogs could not be obtained by the Bridgman technique due to phase separation. Polycrystalline forms of these compounds, obtained by quenching from the melt, are scintillators. •Systematic study of structure and scintillation of La elpasolites and related compositions.•New structures for Cs2NaLaCl6, Cs2NaLaBr6, Cs3LaBr6, and Cs3LaI6.•New scintillators-Ce3+ activated Cs3LaCl6, Cs2NaLaI6 and Cs3LaI6.•Significantly improved scintillation in Cs2NaLaCl6, Cs2NaLaBr6 and Cs3LaBr6.