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Reports on the luminescent properties of europium (Eu) and terbium (Tb) in the SrB6O10 matrix. Information on Eu and Tb; Details on the excitation and emission spectra of SrB6O10.

Abstract: It has been found that charge compensated CaMoO4:Eu3+ phosphors show greatly enhanced red emission under 393 and 467nm-excitation, compared with CaMoO4:Eu3+ without charge compensation. Two approaches to charge compensation, (a) 2Ca2+ →Eu3+ +M+, where M+ is a monovalent cation like Li+, Na+ and K+ acting as a charge compensator; (b) 3Ca2+ →2Eu3+ +vacancy, are investigated. The influence of sintering temperature and Eu3+ concentration on the luminescent property of phosphor samples is also discussed. [Copyright &y& Elsevier]

Abstract: In this study, KMgF3:Eu2+ luminescent nanocrystals (NCs) were prepared in water/cetyltrimethylammonium bromide (CTAB)/2-octanol microemulsions. The KMgF3:Eu2+ NCs were characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), fluorescence spectrum, infrared spectroscopy (IR) and elementary analysis. The results showed that the size of the KMgF3:Eu2+ NCs was hardly affected by water content and surfactant (CTAB) concentration. The emission spectrum showed that the position of the 362nm peak is due to the K+ sites substituted Eu2+. Two emission peaks located at 589 and 612nm can be attributed to Eu3+, which exist at two different types of Eu3+ centers: one is Eu3+ at a K+ site, the other is clustering of Eu3+ ions in the interstices of KMgF3 host lattice. [Copyright &y& Elsevier]

Abstract: In our study, the Eu2+ doped Li2CaSiO4 phosphors were initially synthesized by high temperature solid state method, and their luminescent properties were also investigated. Eu2+ ions occupied 8-coordinatid distorted dodecahedral Ca sites, leading to strong crystal field splitting. The strong crystal field splitting made the broad excitation band extending from UV to visible region. In addition, the high concentration of Li+ ions in the structure constrained the distortion of the emission centers, then resulted in a small stokes shift, ∼1100 cm−1. Under excitation, the Li2CaSiO4:Eu2+ phosphors emitted bluish green light with peak of 480 nm, FWHM of 31 nm and color coordination of (0.06, 0.44). The Eu2+ doped Li2CaSiO4 phosphor would be suitable for bluish green phosphor of white LEDs due to its excellent excitation profile and chromaticity. [Copyright &y& Elsevier]

Abstract: The powder has been hydrothermally synthesized from the double system. The effects of factors such as the ratio of initial reaction, pH value, reaction temperature and time were investigated. Moreover, the : RE (RE=Eu, Tb) phosphors were prepared by the hydrothermal method. Further, they were characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. The luminescent properties were investigated by the luminescence spectrometer. The results show that the molar ratio and pH in the initial reaction mixture associated with the reaction temperature dominate the crystallization of the products. The products are air stable. XPS confirms the oxygen content of those products is very low. : RE obtained was pure phase of . It indicates that doping a low concentration of ions could not change the structure. In the co-doped and system, , and are observed in one matrix. These phenomena can be explained using an electron transfer theory. These RE ions occupy the sites of in . [Copyright &y& Elsevier]

The different ions doped KMgF3 single crystals are prepared by the vertical Bridgman method. The near-infrared absorption spectra for different parts of all as-growth crystals indicate that there is the best transparency in middle part. The correlation between the vibronic frequencies of Eu2+ and the site displacement of Cu+ co-doped ions is firstly studied, which indicates that Cu+ ions replace the site of the Mg2+ ions. The co-doped Eu2+ counteracts the charge misfit causing by the replacement of Mg2+ with Cu+. The overlapping of the emission spectra of the Eu2+ and the excitation spectra of the Cu+ results in the energy transfer from Eu2+ to Cu+. [Copyright &y& Elsevier]

Abstract: The complex fluorides KMF3:Re (M=Mg, Zn; Re=Eu, Ce) were solvothermally synthesized at 180°C and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectroscopy (IR) and spectrofluorometer. In the emission spectrum of KMgF3:Eu powders, there is one sharp line emission located at 360nm, which is arisen from f→f (6P7/2→8S7/2) transition of Eu2+ in KMgF3 lattice. The excitation spectrum of KMgF3:Eu powders monitored at 360nm emission has only one broad peak maximum at about 250nm. In the emission spectrum of KZnF3:Eu, there is one sharp line emission located at 360nm (6P7/2→8S7/2 transition of Eu2+) and one broad range of 370–550nm with a maximum center located at 461nm, which is arisen from d→f (4f65d→8S7/2) transition of Eu2+. The excitation spectrum of KZnF3:Eu monitored at 360nm emission has one broad peak maximum at about 253nm. The typical doublet 5d–4f emission peaks of Ce3+ in KZnF3 powders are shown. [Copyright &y& Elsevier]

Abstract: The complex fluorides Li2BeF4 and LiSrAlF6 were synthesized solvothermally at 180–240 °C and characterized by means of X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS). The different influence factors such as solvents, molar ratios of initial mixtures, reaction temperature and reaction time were investigated. The experimental results indicated that Li2BeF4 and LiSrAlF6 powders could be controllably synthesized in the solvothermal process. [Copyright &y& Elsevier]

A novel long-lasting phosphor CdSiO3:Mn2+ is reported in this paper. The Mn2+-doped CdSiO3 phosphor emits orange light with CIE chromaticity coordinates x=0.5814 and y=0.4139 under 254 nm UV light excitation. In the emission spectrum of 1% Mn2+-doped CdSiO3 phosphor, there is a broad emission band centered at 575 nm which can be attributed to the spin-forbidden transition of the d-orbital electron associated with the Mn2+ ion. The phosphorescence can be seen by the naked eyes in the dark clearly even after the 254 nm UV irradiation have been removed for about 1 h. The mechanism of the origin of the long-lasting phosphorescence was discussed using the thermoluminescence curves. [Copyright &y& Elsevier]

We reported, for the first time to the best of our knowledge, the Sm3+-doped yttrium oxysulfide phosphors has reddish orange long-lasting phosphorescence. The phosphor show prominent luminescence in reddish orange due to the electronic transitions of 4G5/2→6HJ (J = 5/2, 7/2, 9/2), the afterglow color of this type of phosphors is a mixture of the three above mentioned electronic transition emissions and have a little different when the concentration of the Sm3+ dopant changes. Synthesis procedure of the Sm3+-yttrium oxysulfide reddish orange phosphor through the flux fusion method with binary flux compositions was presented. The synthesized phosphors were analyzed using X-ray diffraction (XRD) to interpret the structural characterization. The XRD analysis result reveal that the Y2O2S:Sm3+ phosphor synthesized with a binary flux composition containing (S and Na2CO3 at a ratio of 1:1 at 30 wt.% of total raw material) at 1050 °C for 3 h was in single-phase. Luminescence properties of the Y2O2S:Sm3+ long-lasting phosphor was analyzed by measuring the excitation spectra, emission spectra and afterglow decay curve. The mechanism of the strong afterglow from Y2O2S:Sm3+ was also discussed in this paper. [Copyright &y& Elsevier]

Novel pink light emitting long-lasting afterglow CdSiO3:Sm3+ phosphors are prepared by the conventional high-temperature solid-state method and their luminescent properties are investigated. XRD and photoluminescence (PL) spectra are used to characterize the synthesized phosphors. The phosphors are well crystallized by calcinations at 1050°C for 5 h. These phosphors emit pink light and show long-lasting phosphorescence after they are excited with 254 nm ultraviolet light. The phosphorescence lasts for nearly 5 h in the light perception of the dark-adapted human eye (0.32 mcd/m2). The phosphorescence mechanism is also investigated. All the results indicate that these phosphors have promising potential practical applications. [Copyright &y& Elsevier]

Erbium-doped BaF2 nanoparticles were prepared from the microemulsion of cetyl trimethyl ammonium bromide (CTAB), n-butanol, n-octane and water. The X-ray diffraction (XRD) patterns were indexed to a pure BaF2 cubic phase. Transmission electron microscopy (TEM) images showed that BaF2 products were monodispersed with 15–20 nm in size at the dopant concentration of 0.06 mol%. At higher dopant concentration, there was no significant increase in particle size, but more polydispersed. Photoluminescence (PL) properties of the final products were examined. We can observe fluorescence of Er3+ around 1540 nm and with the increase of dopant concentration, the fluorescent intensity increases. [Copyright &y& Elsevier]

The complex fluoride LiBaF3 and LiBaF3:M(M=Eu, Ce) is solvothermally synthesized at 180°C and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, molar ratios of initial mixtures and reaction temperature play important roles in the formation of products. The excitation and emission spectra of the LiBaF3:M(M=Eu,Ce) have been measured by fluorescence spectrophotometer. In the LiBaF3:Eu emission spectra, there is one sharp line emission located at 360 nm arising from f→f transition of Eu2+ in the host lattice, and typical doublet 5d–4f emission of Ce3+ in LiBaF3 powder is shown. [Copyright &y& Elsevier]

The complex fluorides KMgF3 and KZnF3 with Perovskite structures were solvothermally synthesised at 150–180°C and characterised by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. [Copyright &y& Elsevier]