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Pr3+ doped high density germanate glasses were prepared by the melt-quenching method. The physical and luminescent properties were investigated. The glass containing BaF 2 represented maximum phonon energy of 810 cm−1, and the glass density was greater than 6 g/cm3. The glass exhibited good radiation resistance under 2 h of X-ray irradiation. Intense blue, green emissions and weak red emissions were observed when the glass was excited by X-ray, and the blue fluorescence lifetimes were in the range of 9.15–12.59 μs The results show that Pr3+ doped germanate glass could be a potential scintillating material in the field of X-ray detection for fast events. [ABSTRACT FROM AUTHOR]

Ce3+-doped dense glasses with high light yield (LY) are promising scintillators for use in high-energy particle physics research and radiation sensors for high-energy X- and γ- ray detection. In this work, Ce3+-doped (60-x)SiO 2 -xBaF 2 -20Al 2 O 3 -20Gd 2 O 3 oxyfluoride glasses have been prepared under a CO reducing atmosphere. Substitution of SiO 2 by BaF 2 has been made to increase the density, and the effects on luminescence and scintillation properties have been investigated. The amorphous nature of the prepared glass is confirmed by the XRD profile showing an absence of any diffraction peaks. The broad photoluminescence (PL) emission band of the Ce3+ 5d–4f transition in the 330–580 nm range is observed peaking around 385 nm and the PL decay is governed in the range of 46–53 ns decay time. The 10 mol% BaF 2 glass with density of 4.54 g/cm3 shows the highest LY value of 1590 photons/MeV and energy resolution of 16.5% in the pulse height spectrum of 662 keV γ rays, and the LY of 141 photons/MeV and energy resolution of 21.7% in the pulse height spectrum of 5.5 MeV α particles. • Ce3+-doped (60-x)SiO 2 -xBaF 2 -20Al 2 O 3 -20Gd 2 O 3 (x = 0–20) glasses were prepared under CO atmosphere. • XRD pattern confirms an amorphous nature of the prepared glass. • Gd3+ to Ce3+ energy transfer was observed in the prepared glasses. • Light yield of 1590 photons/MeV at 662 keV γ rays was obtained for 10 mol% BaF 2 containing glass. • Energy transport efficiency in scintillation process increases with increasing BaF 2 content. [ABSTRACT FROM AUTHOR]

The short-wavelength sub-nanosecond luminescence in BaF 2 material, discovered in the early 80s, gave a new direction to research into fast scintillators and phosphors. In contrast to 'typical' luminescence occurring within the forbidden band gap, the new type of emission was due to transitions between the upper core and valence bands. Thus it was named core-valence luminescence (CVL); the terms cross-luminescence and Auger-free luminescence have also been used. Given its unusual nature, this new luminescence process has attracted considerable interest in the field of condensed matter physics. During the sequent decades (till the end of the previous century) CVL has been experimentally observed in several dozen compounds and the conditions for detecting CVL have been established. Interest in this kind of luminescence increased in recent years due to the emergence of new methods of crystal synthesis, the development of high-speed solid-state photodetectors, and the construction of unique modern set-ups using synchrotron radiation. This paper analyzes the numerous studies of CVL, obtained mainly over the past decade. Experimental and theoretical data on this topic are considered in detail. Special attention is given to new results on scintillation characteristics of BaF 2 in the form of single crystals, ceramics, nanoparticles, and composites. The features of CVL in binary and ternary compounds are discussed. Some Cs- and Ba-based ternary halides show relatively high light yields and represent promising fast scintillators. The prospects of using materials with CVL as fast scintillators for time-of-flight positron emission tomography and other applications are deliberated. • Overview of recent theoretical and experimental findings on Core Valence luminescence. • Most attractive CVL crystals for ultrafast scintillator applications analyzed. • Prospects for future studies and underexplored CVL materials listed. [ABSTRACT FROM AUTHOR]