73 research outputs found
Luminescence of sapphire single crystals irradiated with high-power ion beams
Optical absorption, photo- and cathodoluminescence of a sapphire single crystal (α-Al 2 O 3 ) exposed to pulsed nanosecond radiation with high-power ion beams C + /H + with an energy of 300 keV and energy density 0.5-1.5 J/cm 2 were first investigated in this work. It was found that under ion irradiation accompanied by heating of sapphire up to melting, the formation of F-type centers and their aggregates associated with oxygen vacancies was observed in the crystals under study. These centers have luminescence bands at 330, 410 and 500 nm which depend on the type and wavelength of the optical excitation. The appearance of a new PL emission at 435 nm, presumably associated with a complex vacancy-impurity defect, was also observed in the photoluminescence spectra. © Published under licence by IOP Publishing Ltd.The work was supported by the initiative scientific project № 16.5186.2017/8.9 of the Ministry of Education and Science of the Russian Federation. Experiments on ion irradiation of sapphire was done at the KIPT as a part of the state task
Thermoluminescence of Magnesium Oxide Ceramics Obtained by the Method of Electron Beam Synthesis
The luminescent properties of MgO ceramics synthesized by the electron beam method were investigated. The luminescence centers were identified in the samples. The TL curves and dose characteristics of TL peaks excited by a pulsed electron beam (130 keV, 1.5–60 kGy) were analyzed
Self-assembled monolayers of alendronate on Ti6Al4V alloy surfaces enhance osteogenesis in mesenchymal stem cells
Phosphonates have emerged as an alternative for functionalization of titanium surfaces by the formation of homogeneous self-assembled monolayers (SAMs) via Ti-O-P linkages. This study presents results from an investigation of the modification of Ti6Al4V alloy by chemisorption of osseoinductive alendronate using a simple, effective and clean methodology. The modified surfaces showed a tailored topography and surface chemistry as determined by SEM microscopy and RAMAN spectroscopy. X-ray photoelectron spectroscopy revealed that an effective mode of bonding is created between the metal oxide surface and the phosphate residue of alendronate, leading to formation of homogenous drug distribution along the surface. In-vitro studies showed that alendronate SAMs induce differentiation of hMSC to a bone cell phenotype and promote bone formation on modified surfaces. Here we show that this novel method for the preparation of functional coatings on titanium-based medical devices provides osseoinductive bioactive molecules to promote enhanced integration at the site of implantation
Luminescent Properties of Nanostructured Al2O3 Ceramics Irradiated with C+/H+ Pulsed Ion Beams
The luminescent properties of nanostructured α-Al2O3 ceramics irradiated with C+/H+ pulsed ion beams have been studied. The relationship between changes in the TL properties of ceramics and the formation of radiation defects under irradiation is discussed
CATHODO- AND THERMOLUMINESCENCE OF α-Al2O3 SINGLE CRYSTALS IRRADIATED WITH Fe10+ PULSED ION BEAM
PCL and TL of α-Al2O3 single crystals irradiated with various doses of Fe10+ pulsed ion beam were studied. The formation of F-type centers in irradiated crystals was observed. A similar nonmonotonic dependence of PCL of F-centers and TL on the value of the radiation dose was found
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