Search results for "Yttrium"
showing 10 items of 179 documents
Efficacy and safety of yttrium 90 ibritumomab tiuxetan in patients with relapsed or refractory diffuse large B-cell lymphoma not appropriate for auto…
2007
A prospective, multicenter, nonrandomized phase 2 trial was conducted to evaluate the efficacy and safety of a single dose of yttrium-90 (90Y) ibritumomab tiuxetan in elderly patients in first relapsed or primary refractory diffuse large B-cell lymphoma (DLBCL) ineligible for stem-cell transplantation. Patients had been previously treated with chemotherapy (group A, n = 76) or chemotherapy plus rituximab (group B, n = 28). Patients in group A were further divided into patients in whom induction therapy had failed (stratum AI, n = 33) and patients who had relapsed after achieving complete response (CR; stratum AII, n = 43). The overall response rate (ORR) was 52% and 53% in strata AI and AII…
Metallic interconnects for SOFC: Characterisation of corrosion resistance and conductivity evaluation at operating temperature of differently coated …
2007
Abstract One of challenges in improving the performance and cost-effectiveness of solid oxide fuel cells (SOFCs) is the development of suitable interconnect materials. Recent researches have enabled to decrease the operating temperature of the SOFC from 1000 to 800 °C. Chromia forming alloys are then among the best candidates for interconnects. However, low electronic conductivity and volatility of chromium oxide scale need to be solved to improve interconnect performances. In the field of high temperature oxidation of metals, it is well known that the addition of reactive element into alloys or as thin film coatings, improves their oxidation resistance at high temperature. The elements of …
Synthesis of yttrium aluminum garnet nanoparticles in confined environment II: Role of the thermal treatment on the composition and microstructural e…
2017
Abstract Nanoparticles of yttrium aluminum garnet (YAG, Y 3 Al 5 O 12 ) have been obtained by thermal treatments, at several temperature in the range 400–950 °C, of the precursors synthetized via co-precipitation in water in oil microemulsion. The obtained nanoparticles have been characterized by means of X-ray Diffraction and Transmission Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (EDS) and Select Area Electron Diffraction (SAED). Results show the phase evolution occurring to obtain not aggregated nanoparticles of YAG phase. A possible growth mechanism of YAG nanoparticles is discussed on the basis of observed particle microstructure and morphology. The results i…
Interaction Between Oxygen and Yttrium Impurity Atoms as well as Vacancies in fcc Iron Lattice: Ab Initio Modeling
2012
Synthesis of advanced radiation-resistant steels as construction materials for nuclear reactors, which contain the uniformly distributed yttria precipitates (ODS steels), is an important task for ecological security of nuclear plants. The initial stage of theoretical simulation on oxide cluster growth in the steel matrix is a large-scale ab initio modeling on pair- and triple-wise interaction between the Y and O impurity atoms as well as Fe vacancies, including their different combinations, in the paramagnetic face-centered-cubic (fcc) iron lattice. Calculations on the pair of Y atoms have shown that no bonding appears between them, whereas a certain attraction has been found between Y subs…
Synthesis of yttrium aluminum garnet nanoparticles in confined environment III: Cerium doping effect
2018
Abstract 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 h at 900 °C. 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 …
Intrinsic defect related luminescence in ZrO2
2011
The studies of ZrO 2 and yttrium stabilized ZrO 2 nanocrystals luminescence as well as yttrium stabilized single crystal luminescence and induced absorption showed that the intrinsic defects are responsible for luminescence at room temperature. These defects form a quasi-continuum of states in ZrO 2 band gap and are the origin of the luminescence spectrum dependence on the excitation energy. Luminescence centers are oxygen vacancies related but not the vacancies themselves. At room temperature, in ZrO 2 , deep traps for electrons and holes exist. The oxygen vacancies are proposed to be the traps for electrons.
Pulsed laser deposition of epitaxial yttrium iron garnet films with low Gilbert damping and bulk-like magnetization
2014
Yttrium iron garnet (YIG, Y [subscript 3]Fe[subscript 5]O[subscript 12]) films have been epitaxially grown on Gadolinium Gallium Garnet (GGG, Gd[subscript 3]Ga[subscript 5]O[subscript 12]) substrates with (100) orientation using pulsed laser deposition. The films were single-phase, epitaxial with the GGG substrate, and the root-mean-square surface roughness varied between 0.14 nm and 0.2 nm. Films with thicknesses ranging from 17 to 200 nm exhibited low coercivity (<2 Oe), near-bulk room temperature saturation moments (∼135 emu cm[superscript −3]), in-plane easy axis, and damping parameters as low as 2.2 × 10[superscript −4]. These high quality YIG thin films are useful in the investigation…
Synthesis of YAG nanopowder by the co-precipitation method: Influence of pH and study of the reaction mechanisms
2012
International audience; YAG nanopowders with an average grain size of 30 nm have been successfully synthesized by the co-precipitation method using nitrates with precipitant of ammonium hydrogen carbonate. The influence of precipitation conditions such as pH, aging time and calcination temperature on the formation of secondary phases has been studied. The accurate control of pH value at every stage of precipitation process is crucial to avoid the presence of YAM (Yttrium Aluminium Monoclinic, Y4Al2O9) and yttrium oxide (Y2O3) after calcination. The reaction mechanisms have been investigated using different techniques such as infrared spectroscopy, x-ray diffraction and thermal analyses. The…
Effect of the dopant selection (Er, Eu, Nd or Ce) and its quantity on the formation of yttrium aluminum garnet nanopowders
2008
Abstract Hydroxide precursors, synthesized using the co-precipitation method, were calcined for 1 h at the temperatures of 900, 1000 and 1100 °C, respectively, and heated directly to 1500 °C to produce various Y 3 Al 5 O 12 (YAG) nanopowders with different doping quantities of erbium, europium, neodymium and cerium. All samples were investigated using thermo-gravimetry (TG) and differential thermal analysis (DTA), field emission gun-scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). TG and DTA experiments were performed from room temperature up to 1500 °C; the weight loss curves combined with the presence of exo- and endo-thermal even…
Yttrium-doped hematite photoanodes for solar water splitting: Photoelectrochemical and electronic properties
2018
Abstract We investigate yttrium-doped hematite thin-film photoelectrochemical properties and find yttrium incorporation to amply improve the performance as a photoanode for water splitting under visible light. We used the spray pyrolysis method to prepare a set of yttrium doped Fe2-xYxO3 (x = 0, 0.05, 0.10, 0.15, 0.2) thin films (thickness below 500 nm) on glass and transparent conductive oxide coated glass slides. Using a substitutional homovalent (Y3+) dopant, the effect on functionality is rationalised as a combined effect on the electronic structure and small polaron mobility from the lattice structure, impurity levels, lattice stability and variance in hybridisation. The photoelectroch…