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The development and characterization of the optical properties of a neodymium(III)‐doped 42.75AlF3–33.25CaF2–19BaF2–5YF3 (Nd3+‐doped BCA‐5Y) glass in the vacuum ultraviolet (VUV) region are reported. Photoluminescence peaks at 180 and 227 nm are observed upon excitation with the 157 nm emission of a F2 laser. The dominant 180 nm emission peak is assigned to the 4f25d–4f3 (4I9/2 level) transition in Nd3+. This emission peak exhibits a fast, single exponential luminescence with a 16 ns decay time. The strong luminescence intensity and the fast decay time allude to its prospects for scintillator applications. [ABSTRACT FROM AUTHOR]

Time-resolved luminescence properties of Ce3+ doped Y3Al5O12 (YAG) nanocrystals have been studied by means of vacuum-ultraviolet excitation spectroscopy. It was discovered that additionally to the regular Ce3+ yellow-green emission which is well-known luminescence in YAG, new emission covering a broad spectral range from 2.7 eV to 3.5 eV was revealed in the luminescence spectra for all YAG:Ce nanocrystals studied. This blue-UV emission has fast decay time about 7 ns as well as intensive well-resolved excitation band peaking at 5.9 eV and, in contrast to green Ce3+ emission, practically is not excited at higher energies. The origin of the blue-UV emission is tentatively suggested and discussed. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Caesium iodide is one of the most extensively studied scintillators. Here, we present X-ray luminescence spectra, scintillation light output and decay curves as a function of temperature, from room temperature down to below 10 K. Features of the observed intrinsic luminescence are explained in terms of radiative recombination of on- and off-center STE. A model permitting interpretation of the dynamics of luminescence changes in CsI with temperature is suggested. This model includes adiabatic potential energy surfaces (APES) associated with singlet and triplet states of self-trapped excitons (STE) and explains the variation of the luminescence spectra with temperature as a result of re-distribution in the population between on- and off-center STE. The temperature dependence of the scintillation light yield is discussed in the framework of the Onsager mechanism. [ABSTRACT FROM AUTHOR]

Singulett ‐ Biradikaloide der Hauptgruppenelemente wurden in den letzten 20 Jahren gründlich untersucht, insbesondere Derivate des Cyclobutan ‐ 1,3 ‐ diyls. Jedoch sind in jedem der bekannten Beispiele die Radikalzentren äquivalent. Daher wollten wir ein gemischtes Dipniktadiazandiyl herstellen, in dem P und As den Radikalcharakter tragen. Um das Ziel zu erreichen, musste zunächst das Dichlorcycloarsaphosphadiazan [ClP(μ ‐ NTer)2AsCl] synthetisiert werden. Durch Chloridabstraktion von [ClP(μ ‐ NTer)2AsCl] wurde das cyclische Kation [P(μ ‐ NTer)2AsCl]+ erhalten, während die Reduktion mit Magnesium zum Arsaphosphadiazandiyl [P(μ ‐ NTer)2As] führte. Wenn man zu zweit ist, kann man nicht zu radikal sein: Das erste Biradikaloid mit unterschiedlichen Radikalzentren, das heteroatomare Biradikaloid [P(μ ‐ NR)2As], wurde durch Reduktion des entsprechenden Dichlorarsaphosphadiazans mit Magnesium erhalten. Die Molekülstruktur weist für den planaren viergliedrigen N2PAs ‐ Ring eine charakteristische Drachenform mit zwei gleichen P ‐ N ‐ und As ‐ N ‐ Abständen auf. CASSCF ‐ Rechnungen belegen einen Biradikalcharakter von 28 %. [ABSTRACT FROM AUTHOR]

Recent developments of plastic scintillators are reviewed, from 2000 to March 2014, distributed in two different chapters. First chapter deals with the chemical modifications of the polymer backbone, whereas modifications of the fluorescent probe are presented in the second chapter. All examples are provided with the scope of detection of various radiation particles. The main characteristics of these newly created scintillators and their detection properties are given. [ABSTRACT FROM AUTHOR]