Controlling the europium oxidation state in diopside through flux concentration.

This paper explores the connection between the HBO flux concentration and the co-existence of Eu and Eu dopants within CaMgSiO crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N), and reductive (H/N mixture) environments. Additionally, some materials underwent chemical modification by partially substituting Si with Al ions acting as charge compensation defects stabilizing Eu luminescence.

Lanthanide ions (Eu, Er, Pr) as luminescence and charge carrier centers in SrTiO.

A series of strontium orthotitanate (SrTiO) samples doped with 2% of a mole of europium, praseodymium, and erbium were obtained using the solid-state synthesis method. The X-ray diffraction (XRD) technique confirms the phase purity of all samples and the lack of the influence of dopants at a given concentration on the structure of materials. The optical properties indicate, in the case of SrTiO:Eu, two independent emission (PL) and excitation (PLE) spectra attributed to the Eu ions at sites with different symmetries: low - excited at 360 nm and high - excited at 325 nm, while, for SrTiO:Er and SrTiO:Pr, the emission spectra do not depend on the excitation wavelength.

Energetic structure of Sm luminescence centers in SrTiO.

A luminescent material based on the strontium orthotitanate (SrTiO) matrix doped with 1% of a mole of samarium was obtained using the typical solid-state synthesis method under a neutral atmosphere of nitrogen. The sample was investigated using powder X-ray diffraction (XRD) and several luminescence techniques to study the phase composition, luminescence properties as well as to determine the position of the energetic states of Sm in relation to the valence and conduction bands of SrTiO. The XRD result shows that the product of the synthesis is pure SrTiO.

Influence of Al co-doping on the spectral properties of europium doped CaY(PO).

A series of luminescent materials based on a calcium yttrium phosphate matrix doped with europium and different concentrations of aluminum ions (0, 5, 10% of mole) was synthesized using the Pechini method. A two-step strategy of synthesis was applied. Phase composition analysis and spectroscopic measurements were performed to characterize the obtained phosphors.

Up-conversion white emission and other luminescence properties of a YAG:YbO·TmO·HoO@SiO glass-nanocomposite.

We report on a glass-nanocomposite material consisting of yttrium aluminum garnet (YAlO, YAG) nanocrystals co-doped with Yb, Tm and Ho ions as well as entrapped into a SiO xerogel. This 94YAG·5YbO·0.8TmO·0.

Spectroscopic properties and location of the Tb(3+) and Eu(3+) energy levels in Y2O2S under high hydrostatic pressure.

In this contribution, an extensive spectroscopic study of Y2O2S doped with Eu(3+) and Tb(3+) is presented. Steady-state luminescence and luminescence excitation spectra as well as the time-resolved spectra and luminescence kinetics were obtained at high hydrostatic pressures up to 240 kbar. It was found that pressure quenches the luminescence from the (5)D3 excited state of Tb(3+) and recovers additional luminescence related to transitions from the (5)D3 state of Eu(3+).

Equation of state for Eu-doped SrSi₂O₂N₂.

α-SrSi2O2N2 is one of the recently studied oxonitridosilicates applicable in optoelectronics, in particular in white LEDs. Its elastic properties remain unknown. A survey of literature shows that, up to now, nine oxonitridosilicate materials have been identified.

Time evolution of luminescence of Sr₂SiO₄:Eu²⁺.

In this contribution, the photoluminescence, time-resolved luminescence and luminescence kinetics of α'-Sr2SiO4:Eu(2+) are studied. The luminescence of Sr2SiO4:Eu(2+) consists of two broad bands, peaked at 490 nm (blue-green) and 570 nm (yellow-orange), which originate from two luminescence centers, related to Eu(2+) in ten-coordinated SI and nine-coordinated SII sites, respectively. Based on spectroscopic data the energetic structure of Sr2SiO4:Eu(2+) has been developed, which includes the bands edges, energies of Eu(2+) in the SI and SII sites and energies of strontium and oxygen vacancies.