Graphene coating obtained in a cold-wall CVD process on the Co-Cr Alloy (L-605) for medical applications

Graphene coating on the cobalt-chromium alloy was optimized and successfully carried out by a cold-wall chemical vapor deposition (CW-CVD) method. A uniform layer of graphene for a large area of the Co-Cr alloy (discs of 10 mm diameter) was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW-CVD process on the microstructure and the mor-phology of the Co-Cr surface was investigated by scanning X-ray photoelectron microscope (SPEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Nanoindentation and scratch tests were performed to determine mechanical properties of Co-Cr disks. The results of microbiological tests indicate that the studied Co-Cr alloys covered with a graphene layer did not show a pro-coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular diseases

Sicilian byzantine icons through the use of non-invasive imaging techniques and optical spectroscopy: The case of the madonna dell’elemosina

The iconographic heritage is one of the treasures of Byzantine art that have enriched the south of Italy, and Sicily in particular, since the early 16th century. In this work, the investigations of a Sicilian Icon of Greek-Byzantine origin, the Madonna dell’Elemosina, is reported for the first time. The study was carried out using mainly non-invasive imaging techniques (photography in reflectance and grazing visible light, UV fluorescence, infrared reflectography, radiography, and computed tomography) and spectroscopic techniques (X-ray fluorescence and infrared spectroscopy). The identification of the constituent materials provides a decisive contribution to the correct historical and artistic placement of the Icon, a treasure of the Eastern European historical community in Sicily. Some hidden details have also been highlighted. Most importantly, the information obtained enables us to define its conservation state, the presence of foreign materials, and to direct its protection and restoration

Graphene Coating Obtained in a Cold Wall CVD Process on the Co Cr Alloy L 605 for Medical Applications

Graphene coating on the cobalt chromium alloy was optimized and successfully carried out by a cold wall chemical vapor deposition CW CVD method. A uniform layer of graphene for a large area of the Co Cr alloy discs of 10 mm diameter was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW CVD process on the microstructure and the morphology of the Co Cr surface was investigated by scanning X ray photoelectron microscope SPEM , atomic force microscopy AFM , scanning electron microscopy SEM , and energy dispersive X ray spectroscopy EDS . Nanoindentation and scratch tests were performed to determine mechanical properties of Co Cr disks. The results of microbiological tests indicate that the studied Co Cr alloys covered with a graphene layer did not show a pro coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular disease

Synthesis and down conversion emission property of Eu3+ doped LaAlO3 CsAlO2 and LiLaO2 phosphors

[EN] LaAlO3:Eu3+, CsAlO2:Eu3+ and LiLaO2:Eu3+ phosphors with varying concen- trations of Eu3+ from 3 to 10 mol% were prepared by combustion synthesis method and the samples were further heated to 1,000ºC to improve the crystallinity of the materials. The structure and morphology of materials have been examined by X-ray diffraction and scan- ning electron microscopy. SEM images depicted that the morphology of crystallites have no uniform shapes and sizes. Small and coagulated particles of irregular shapes of different sizes are obtained. The characteristic emissions of Eu3+ were clearly observed at nearly 580, 592, 650, 682 to 709 (multiplet structure) nm for 5D - 7 Fn transitions where n = 0, 1, 3, 4 respectively, including the strongest emission peaks at 614 and 620 nm for 5 D0 - 7 F2 transitions in CsAlO2:Eu3+ and LiLaO2:Eu3+ host lattices. The intensity of emission peak corresponding to 5 D0 !→ 7 F1 transitions in LaAlO3 :Eu3+ material is comparable to that of 5D0 5D-7F2 transitions which is also a singlet. Photoluminescence intensity follows the order as in LiLaO2 > LaAlO3 > CsAlO2 lattices. Remarkable high photoluminescence intensity with 7 mol% doping of Eu3+ in LiLaO2 makes it a strong contender for red colored display applications.This work was supported by the European Commission through Nano CIS project (FP7-PEOPLE-2010-IRSES ref. 269279).Marí Soucase, B.; Singh, KC.; Moya Forero, MM.; Singh, I.; Om, H.; Chand, S. (2015). Synthesis and down conversion emission property of Eu3+ doped LaAlO3 CsAlO2 and LiLaO2 phosphors. Optical and Quantum Electronics. 47(7):1569-1578. https://doi.org/10.1007/s11082-014-9997-9S15691578477Abbattista, F., Vallino, M.: Remarks on the $$\text{La}_{2}\text{O}_{3}-\text{Li}_{2}\text{O}$$ La 2 O 3 - Li 2 O binary system between 750 and 1,000  $$^{\circ}$$ ∘ C. Ceram. 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Synthesis, structure and luminescence of Er3+-doped Y3Ga5O12 nano-garnets

A novel Y3(1-x)Er3xGa5O12 nanocrystalline garnet has been synthesized by a sol-gel technique and a complete structural, morphological, vibrational, and optical characterization has been carried out in order to correlate the local structure of the Er3+ ions with their optical properties. The synthesized nanocrystals are found in a single-phase garnet structure with an average grain size of around 60 nm. The good crystalline quality of the garnet structure is confirmed by FTIR and Raman measurements, since the phonon modes of the nano-garnet are similar to those found in the single crystal garnet. Under blue laser excitation, intense green and red visible and 1.5 mu m infrared luminescences are observed, whose relative intensities are very sensitive to the Er3+ concentration. The dynamics of these emissions under pulsed laser excitations are analyzed in the framework of different energy transfer interactions. Intense visible upconverted luminescence can be clearly observed by the naked eye for all synthesized Er3+-doped Y3Ga5O12 nano-garnets under a cw 790 nm laser excitation. The power dependency and the dynamics of the upconverted luminescence confirm the existence of different two-photon upconversion processes for the green and red emissions that strongly depend on the Er3+ concentration, showing the potential of these nano-garnets as excellent candidates for developing new optical devices.This work has been partially supported by Ministerio de Ciencia e Innovacion of Spain (MICCIN) under The National Program of Materials (MAT2010-21270-C04-02; -03; -04), The Consolider-Ingenio 2010 Program (MALTA CSD2007-0045), and The National Infrastructure Program, by Ministerio de Economia y Competitividad of Spain (MINECO) within The Indo-Spanish Joint Programme of Cooperation in Science and Technology (PRI-PIBIN-2011-1153/DST-INT-Spain-P-38-11), and by the EU-FEDER funds (UCAN08-4E-008). S.F. Leon-Luis and V. Monteseguro wish to thank MICINN for the FPI grants (BES-2008-003353 and BES-2011-044596). Dr V. Venkatramu is grateful to DAE-BRNS, Government of India for the award of DAE Research Award for Young Scientists (no. 2010/20/34/5/BRNS/2223).Venkatramu, V.; León-Luis, SF.; Rodriguez-Mendoza, UR.; Monteseguro, V.; Manjón, FJ.; Lozano-Gorrín, AD.; Valiente, R.... (2012). Synthesis, structure and luminescence of Er3+-doped Y3Ga5O12 nano-garnets. Journal of Materials Chemistry. 22:13788-13799. doi:10.1039/c2jm31386cS13788137992

Synthesis of yttrium aluminum garnet nanoparticles in confined environment III: Cerium doping effect

Cerium yttrium aluminum garnet (Ce:YAG, CexY3-xAl5O12) nanoparticles doped with different cerium amount were obtained by calcining the precursors synthesized via co-precipitation in w/o microemulsion for 1\u202fh\u202fat 900\u202f\ub0C. The structural and morphological properties were investigated by using X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Transmission Electron Microscopy (TEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) in order to investigate the effect of doping level on formation and microstructure of obtained nanoparticles. It was found that the composition of the final products strongly depends on the concentration of cerium. The formation of single YAG phase was observed only at 0.5% cerium. For other concentrations, a mixture of YAG and yttria phases was obtained indicating an effect of the cerium on stabilization of sesquioxide phase. Optical properties of the single phase powder were also investigated in details

Rare-Earth Doped Nanocrystalline Phosphors for Field Emission Displays

The cathodoluminescence properties of rare-earth (RE = Ce, Eu, Tb) doped nanocrystalline phosphors (Y2O3, Y3Al5O12) were investigated. Their structure and morphology were determined and correlated with optical properties. The effect of grain sizes on emission yield of RE doped nanophosphors has been investigated. A possibility of application of RE doped nanophosphors for efficient field emission display (FED) devices has been discussed

Spectroscopic investigations of nanostructured LiNbO3 doped with Eu3+

Structural and optical properties of the sol-gel derived nanocrystalline lithium niobate (LiNbO3) powders doped with Eu3+ ions have been studied. In particular, the influence of the sizes of nanoparticles controlled by temperature on the structural and luminescence properties has been investigated. Emission bands corresponding to 5D0 emission became more resolved with increasing nanocrystal size and changed to a typical Eu3+:LiNbO3 single crystal spectrum for nanocrystals having an average size of more than 40 nm. Nonlinear optical properties of nanostructured LiNbO3 have been confirmed by simple observation of second harmonic generation effect (SHG). The possibility of using nanostructured LiNbO3 doped with rare-earth ions as self-doubling elements in integrated optoelectronic devices has been discussed