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Latent tracks in bulk yttrium-iron garnet crystals irradiated with low and high velocity krypton and xenon ions
摘要： Bulk yttrium-iron garnet (YIG) single crystals have been irradiated with swift Kr and Xe ions having energies from 0.4 to 22.8 MeV/u and electronic stopping powers from 8.9 to 28.9 keV/nm near the irradiated surface. Transmission electron microscopy (TEM) has been used for direct observation of non-overlapping amorphous latent tracks in the near surface region of the irradiated bulk YIG crystals. The amorphous track radii observed in this work have been compared with previously reported data from direct and indirect measurements. It was found that the thickness of the sample subjected to swift heavy ion irradiation does not significantly affect the resulting amorphous track size observed by TEM in YIG. The results also support previously observed consistency between direct TEM and indirect Rutherford backscattering in channelling mode (RBS/C) and Mossbauer spectroscopy (MS) methods for amorphous track evaluation in YIG when electronic stopping power is greater than ～13 keV/nm, which is sufficient to create cylindrical amorphous tracks by high velocity ions (E > 10 MeV/u). Indirect methods provide underestimated values compared to TEM when the electronic stopping power is below ～13 keV/nm, for which discrete amorphous tracks are supposed to be formed by high velocity ions.
关键词： Transmission electron microscopy,Latent tracks,Radiation damage,Yttrium-iron garnet,Swift heavy ions
更新于2025-09-09 09:28:46
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Influence of Yttrium Dopant on the Structure and Electrical Conductivity of Potassium Sodium Niobate Thin Films
摘要： KNN thin films with diverse yttrium concentration (mol % = 0, 0.1, 0.3, 0.5, 0.7 and 0.9) were fabricated using sol-gel spin coating technique. Doped KNN revealed that Y3+ was successfully doped into the ABO3 perovskite lattice without changing the phase formation of KNN. The thickness of the deposited layer of KNN produced with increasing dopant concentration was determined to be 200 nm with dense and well-defined grains. Afterwards, the vibrational bonding and conductivity of KNN films with diverse yttrium concentration were identified according to the charge compensation mechanism. At high dopant concentration of > 0.5 mol %, O-Nb-O bonding was asymmetric and became distorted due to B-site occupancy by yttrium dopant. Further investigation revealed that charge compensation mechanism was shifted by increasing doping concentration. As a result, yttrium-doped KNN became semi-conductive at low yttrium concentration. Meanwhile, at high concentration, yttrium-doped KNN became an insulator and underwent ionic compensation.
关键词： yttrium,thin film,doped,structural,KNN,conductivity
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Dispersity and Surface Characterization of Yttrium Vanadate and Phosphate Based Luminescent Phosphors
摘要： The surface properties of Eu(III)-activated yttrium vanadate, yttrium phosphate and mixed yttrium vanadate-phosphate phosphors with different europium content synthesized via self-propagating high temperature synthesis are studied by low temperature nitrogen adsorption, scanning electron microscopy, aqueous slurry pH measurements and adsorption of acid-base indicators. Among the materials synthesized under similar conditions, phosphate based phosphors possess with a significantly more acidic surface (due to the presence of Lewis acidic centers probably corresponding to phosphorous atoms) and coarse dispersity compared with vanadate analogs, while mixed vanadate-phosphate compounds feature with the most fine dispersity.
关键词： Lewis centers,vanadate,yttrium,luminescent phosphor,phosphate,adsorption,surface,Br?nsted centers
更新于2025-09-09 09:28:46
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Synthesis of yttrium doped BiOF/RGO composite for visible light: Photocatalytic applications
摘要： In this present work, yttrium doped bismuth oxy fluoride/reduced graphene oxide (Y-BiOF/RGO) composite was synthesized using a simple solvothermal method. As synthesized composite was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The photocatalytic property was evaluated towards the degradation of methylene blue (MB) dye under the visible-light irradiation. The characterization results highlighted that the efficient incorporation of both yttrium ions and RGO greatly reduced the recombination rate of BiOF and extended the visible-light absorption ability. As synergistic effects, the prepared Y-BiOF/RGO composite exhibited maximum degradation rate of 98% in 360 min, which is 6.5 times higher than pure BiOF. The clear mechanism for the enhanced photo-activity by Y-BiOF/RGO was discussed.
关键词： Semiconductors,BiOF,Photocatalysts,Yttrium,Graphene,Visible light
更新于2025-09-04 15:30:14
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A new design of the YIG/MTC joint brazed by bismuth-based glass
摘要： The paper uncovers an underlined mechanism of joining Yttrium Iron Garnet (YIG) and Magnesium Titanate Ceramic (MTC) with a bismuth-based glass braze. The proposed joint design has not been investigated until present. The central hypothesis is as follows. The brazed bismuth-based glass microstructure and the resulting mechanical strength of a YIG/MTC joint design support favorably a good bonding of the interface domains. The supporting evidence includes the following: (i) the bismuth-based glass features good wettability on YIG and MTC, (ii) the sequence of the coefficients of thermal expansions (YIG, bismuth-based glass, MTC) is in a favorable succession. The study reveals that the interface reactions form: (i) a lamellar phase and YBO3 whiskers at the YIG/Bi25 interface, (ii) both MgFe2O4, and Bi4Ti3O12 whiskers in addition to Zn2Ti3O8 reaction layer at the MTC/Bi25 interface, and (iii) Fe2O3 phase along the brazing seam. The mechanical integrity of joints has been studied as well.
关键词： Magnesium titanate ceramic,Whiskers,Microstructure,Bismuth-based glass braze,Yttrium iron garnet ferrite
更新于2025-09-04 15:30:14
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Investigation of Interface Diffusion in Sputter Deposited Gd0.1Ce0.9O1.95 Thin Buffer Layers on Y-Stabilized Zirconia Crystalline Substrates for Solid Oxide Cells Applications
摘要： This paper presents the results concerning the investigation of the morphological and structural properties of Gd0.1Ce0.9O1.95 layers deposited on crystalline (111) YSZ subtrates by RF magnetron sputtering. Room temperature as-grown samples have been annealed at different temperatures from 600°C to 1300°C. Atomic Force Microscopy analysis shows an increase in the average grain size dimensions with increasing annealing temperatures. X-Ray Diffraction measurements indicates a preferential growth of the grains along the (111) direction with a decrease in the evaluated c-axis as a function of the annealing temperature, probably related to an over-oxidation of the samples. X-Ray Reflectivity studies, performed on thin layers annealed at temperatures from 700-1000°C, points out the presence of zones with different densities and roughness at the layer/substrate interface and at the layer/vacuum surface. The behaviour of these zones as a function of temperature has been investigated. The obtained results seem to exclude the presence of consistent inter-diffusion phenomena at the GDC/YSZ interface.
关键词： Solid oxide cells,X-ray reflectivity,Reciprocal space map,RF magnetron sputtering,Yttrium stabilized Zirconia,Gadolinium doped Ceria,Interdiffusion
更新于2025-09-04 15:30:14
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<i>In My Element</i> : Yttrium
摘要： After a near 7-year pathway devoted solely to late transition metal systems, my hunt in the world of catalysis drove me progressively towards the very left side of the periodic table. Group 4, then group 3, and now group 2 elements. Rare-earths and alkali-earths are really unique elements. Even though going down those two columns and running through the lanthanide row, physicochemical properties most often vary monotonously, their reactivity remains sometimes quite mysterious: who has ever truly rationalized the “peak activity” of neodymium catalyst systems in diene and ethylene polymerization?! But my favorite element isn’t neodymium: its paramagnetism makes for too nasty an NMR spectra to satisfy a molecular chemist in the search for understanding what’s going on in the coordination sphere… No, my special one is yttrium. This one is diamagnetic, providing beautiful, informative NMR spectra. And, importantly for the single-site polymerization catalysis community, some complexes of this abundant element have proved really unique in the ring-opening polymerization of cyclic esters, featuring high activity and unequaled stereocontrol abilities—not unrelated to its small size, which makes for a crowded, discriminative coordination sphere.
关键词： rare-earths,polymerization,alkali-earths,yttrium,catalysis
更新于2025-09-04 15:30:14