Ytterbium Content Research Articles

METAL AND MINERAL MICROINCLUSIONS IN ADAKITES FROM THE FRAMING OF THE UTANAK MASSIF (STANOVOI SUPERTERRANE, RUSSIAN FAR EAST) AS EVIDENCE FOR METAL ENRICHMENT IN ADAKITIC MAGMAS

Porphyritic amphibole–plagioclase andesites at the southern margin of the Utanak ultramafic massif (Stanovoi superterrane, Russian Far East) show low yttrium and ytterbium contents and high Sr/Y and La/Yb ratios typical of adakites. Microinclusions in these volcanic rocks are Cu–Ag–Au alloys, native silver, composites of gold and silver with Cu, Zn, In, Mn, Ni, and Mo minerals, as well as microparticles of platinum, silver sulfides and chlorides, pyrrothite, chalcopyrite, barite, tungsten oxide, crocoite, and cassiterite. The structural features of some microinclusions and their association with primary amphibole and plagioclase suggest their magmatic origin, while other microinclusions hosted in the quartz–chlorite–K-feldspar groundmass formed during later metasomatism. The Utanak adakites are characterized by elevated gold contents (up to 134 ppb) and, together with other manifestations of Mesozoic adakitic magmatism within the Stanovoi superterrane (Il’deus, Lucha, and Gabbrovyi massifs), are classified as ore–bearing (fertile) adakites according to geochemical criteria. We suggest that common association of adakitic magmatism with large porphyry, epithermal, and skarn deposits at convergent plate boundaries is related not only to the high water content and the oxidation state of adakitic magmas but also to the initial enrichment of the latter in various ore components.

THEORETICAL INVESTIGATION FOR YTTERBIUM EFFECT ON RADIATION SHIELDING CHARACTERISTICS OF 50Bi2O3-15Li2O-15PbO-(20-X)B2O3-Yb2O3 BORATE GLASSES

As the nuclear industry has developed and radiation technologies have become more widely used, the dose of radiation from both synthetically produced sources and radioisotopes has increased, as has the number of people being irradiated. It is of the utmost importance to utilise appropriate shielding materials in order to reduce the negative effects of radiation sources. Doped glasses are among the most significant candidate materials in the field of radiation shielding. To this end, it was aimed to investigate the charged particle, gamma-ray and neutron shielding characteristics of ytterbium doped glasses with composition of 50Bi2O3-15Li2O-15PbO-(20-x)B2O3-Yb2O3 (where x = 0.5, 1.0, 1.5, 2.0 and 2.5). In this regard, the radiation shielding parameters were estimated by using Phy-X/PSD, PAGEX, ESTAR, and SRIM codes. Furthermore, the results were compared comprehensively and comparatively. Charged particle (alpha, proton and electron), gamma ray and neutron shielding efficiencies were found to be proportional to ytterbium content. The glasses with the increasing amount of ytterbium exhibited higher shielding performances. It can be said that all the studied glasses and particularly Yb2.5 sample could be used as shielding materials in many radiation related applications.

STRUCTURAL, OPTICAL, AND VISIBLE-LIGHT DRIVEN PHOTACATALYTIC PROPERTIES OF Yb-DOPED BiVO4 NANOPARTICLES PREPARED VIA RAPID SONOCHEMICAL PROCESS

This work represents the synthesis and structural, morphological, and optical characterization of rare-earth Yb-doped BiVO4 materials with different Ytterbium (Yb3+) contents (0% - 5%). Yb-doped BiVO4 specimens in form of fine nanoparticles were synthesized by a rapid and facile sonochemical process. The structural and morphological characterizations were observed by X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Important optical properties of the prepared samples were investigated by the diffuse reflectance technique and the corresponding optical band gaps were calculated by the mean of the Kullbelka-Munk equation. From the characterized results, it is acknowledged that incorporated Yb dopant has a significant effect on the crystalline structure of BiVO4 by reducing in monoclinic phase in the pristine sample while the increasing Yb doping composition resulted in the mixed phases of monoclinic and tetragonal phases since Yb3+ ions could probably induce the stabilization of the tetragonal phase in BiVO4 material. Moreover, extensive doping with Yb3+ exhibits considerable influence on not only structural but also optical and relevant visible - driven photocatalytic properties of BiVO4 by means of the color degradation of RhB dye solution.

Exploring ferroelectric properties of sol-gel lead zirconate titanate nano-crystalline thin films and ceramics by doping ytterbium for energy-storage application

This work concerns how ytterbium affects the ferroelectric characteristics of sol-gel Yb doped lead zirconate (PYZ) and lead zirconate titanate (PYZT) thin films and ceramics. Lead zirconate Pb(0.9) )-Yb0.01 Zr (0.09 (PYZ) and lead zirconate titanate Pb0.9-Yb0.01-Zr0.045-Ti0.045 (PYZT) doping with ytterbium thin films were prepared on a glass substrate using a sol-gel doctor blade coating technique at low temperature. The structure of the synthesized thin films and ceramic nanocrystals was examined using X-ray diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction (ED). PYZ and PYZT ceramics had 11.8 nm and 30.65 nm respectively, whereas PYZ and PYZT thin films featured nanocrystals that were, respectively, 17.5 nm and 13.87 nm in size. Particle size was determined to be entirely consistent across the TEM and XRD data. Dielectric investigations showed that the dielectric constant was dropping for ceramic samples as compared to thin film samples. According to hysteresis loop estimates, the energy-storage density and efficiency for thin films and ceramics were average approximately 39.35 J cm−3 and 66.02 percent for (PYZ) and 71.33 J cm−3 and 70.91 percent for (PYZT), respectively. The results showed that the ferroelectric, dielectric, and structural properties of materials affected the ytterbium content. (PYZ) and (PYZT) thin films and ceramics may have a prospective use in energy storage devices.

Ytterbium-Doped Lead-Halide Perovskite Nanocrystals: Synthesis, Near-Infrared Emission, and Open-Source Machine Learning Model for Prediction of Optical Properties.

Lead-halide perovskite nanocrystals are an attractive class of materials since they can be easily fabricated, their optical properties can be tuned all over the visible spectral range, and they possess high emission quantum yields and narrow photoluminescence linewidths. Doping perovskites with lanthanides is one of the ways to widen the spectral range of their emission, making them attractive for further applications. Herein, we summarize the recent progress in the synthesis of ytterbium-doped perovskite nanocrystals in terms of the varying synthesis parameters such as temperature, ligand molar ratio, ytterbium precursor type, and dopant content. We further consider the dependence of morphology (size and ytterbium content) and optical parameters (photoluminescence quantum yield in visible and near-infrared spectral ranges) on the synthesis parameters. The developed open-source code approximates those dependencies as multiple-parameter linear regression and allows us to estimate the value of the photoluminescence quantum yield from the parameters of the perovskite synthesis. Further use and promotion of an open-source database will expand the possibilities of the developed code to predict the synthesis protocols for doped perovskite nanocrystals.

Investigation of the ytterbium reduction process in the synthesis of Al – Yb master alloys for the modification of aluminum alloys

This work investigates the synthesis process and characterization of a novel type of aluminum-ytterbium master alloy in molten salts. The significance of the obtained results for the research conducted in the field so far is due to the previously proven effectiveness of the influence of ytterbium on the structure and properties of aluminum alloys. During experimental work, the thermodynamic analysis of the aluminothermic process of ytterbium fluoride reduction from molten salts was performed and revealed that the process might occur and develop in the presence of sodium fluoride and potassium chloride if the NaYbF4 precursor is formed. Subsequently, the temperature intervals of thermal effects during the process of reduction of ytterbium from its fluoride in molten salts (NaF – KCl) by aluminum were determined as a result of thermal analysis. During Al – Yb master alloys synthesis experiments, the maximal value of ytterbium extraction to master alloy of 82.5% was achieved by changing the process parameters, such as temperature, reaction time, and molten salts/aluminium ratios. Besides, master alloys containing ytterbium from 1.1 to 5.1 wt.% were synthesized using the optimized technological process conditions and examined with metallographic analysis. The analysis revealed that the microstructure of the synthesized master alloys is presented by eutectic colonies of Al + Al3Yb composition located along the boundaries of α-Al dendritic cells. It was found that about 85.5% of the area of the studied samples with ytterbium content of 5.1 wt.% consist of aluminum dendrites with an average cell size of 25 μm. The presented in this research results are of significant importance for the development of cheap and high-quality aluminum alloys.

Down- and up-conversion processes in Nd3+/Yb3+ co-doped sodium calcium silicate glasses with concomitant Yb2+ assessment

Novel Nd3+/Yb3+ co-doped sodium calcium silicate glasses were prepared by melting quenching method. Spectroscopic study was carried out as a function of doping content by fixing sensitizer (Nd3+) concentration to 0.2 mol% and adjusting activator (Yb3+) from 0 to 1.0 mol%. The energy transfer (ET) mechanisms between Nd3+ and Yb3+ are discussed based on their energy levels and excitation power-dependence emission intensity. Results show that the presence of Yb2+ might be considered for the Nd3+-free and co-doped samples. The ET was confirmed by the down-conversion NIR emission spectra of the doped and co-doped samples under excitation at 808 nm. The mechanisms observed seem to involve only one VIS absorbed photon for each NIR emitted via direct energy transfer between 4F3/2 of Nd2+ and 2F5/2 of Yb3+ compensated by phonon assistance due to energy gap between these levels. The efficiency of ET increases with the ytterbium content up to almost 90% for the sample with 1 mol% of Yb2O3, which was evaluated by lifetime measurements. Up-conversion photoluminescence by exciting trivalent ions of neodymium (808 nm) and ytterbium (975 nm) is reported. The observed up-converted emission bands are related to the 4f-4f transitions of Nd3+ and the spin-forbidden 5d-4f transition of Yb2+. Nd3+ up-conversion emission is observed under 975 nm excitation, presenting an almost quadratic emission dependence with power excitation, which suggests that two laser photons participate in the up-conversion (UC) process, showing that ET occurs by a phonon-assisted energy transfer and cooperative energy transfer.

Effect of Yb-doping on structural and electrical properties of BiFeO3 thin films

In this paper, the incorporation of ytterbium into the BiFeO3 thin film was fabricated on the Pt/Ti/SiO2/Si substrates by using both dc and rf magnetron co-sputtering method at room temperature. The impact of ytterbium content on structural properties and electrical characteristics of the BiFeO3 thin films was investigated. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy techniques were applied to examine the crystal structures, elemental compositions, microstructures, and film morphologies of these thin films, respectively. The Yb-doped BiFeO3 thin film fabricated at the 11 W condition exhibited the lowest leakage current and the highest remnant polarization among these conditions. This result is attributed to the formation of a stronger BiFeO3 (202) component leading to the decrease in oxygen vacancies.

Use of dielectric nanoparticles doped with Yb3+ ions to enhance the thermal effect in a biological tissue exposed to near-IR laser radiation (in vivo experiments)

The conditions for the appearance of broadband radiation from particles of zirconium dioxide stabilised by ytterbium oxide upon excitation by intense laser radiation with a wavelength of 980 nm are investigated. It is shown that this radiation is observed at a lower excitation power density and lower ytterbium content than in particles of orthophosphates and their hydrates. As a result of in vivo experiments, the possibility of using ytterbium-containing particles to enhance the thermal effect from exposure to laser radiation with a wavelength of 980 nm on the skin of a rat is demonstrated.

Probing structure of ytterbium stabilized Pr-doped zirconia obtained by microwave hydrothermal method

Nanoparticles of ZrO2:Pr stabilized with ytterbium in the range 0.5%mol.-20%mol. were synthesized. Crystallite sizes depended on Yb concentration. Red luminescence resulting from 1D2→3H4 transition of Pr3+ is present in all the samples. Additionally in the samples calcined at 1200 °C blue-green luminescence from 3P0 level of Pr3+ was found. This emission was more intense than red one. Intensity of the 3P0→3H4 luminescence depended on ytterbium content and was found to be the highest at 20% mol. Yb. Luminescence study had shown, that ytterbium introduced additional lattice defects. Some quantity of praseodymium activator ions were found to be present at +4 state and changed its valence to +3 as ytterbium content had risen.

Optical properties of ytterbium doped oxyfluoride glass-ceramics - Concentration and temperature dependence studies for optical refrigeration applications

Oxyfluoride glass-ceramics (GCs) doped with lanthanides have recently attracted much attention as a novel optoelectronic material candidate for optical refrigeration. In this study, the optical properties of highly transparent (~90% in the near infrared region) ytterbium doped germanate and aluminosilicate oxyfluoride glass ceramics with different rare earth ion concentrations varying from 0.5 to 3.0 mol % synthesized by the conventional melt quenching technique have been investigated to determine and compare their potential for optical refrigeration applications. The photoluminescence (PL) emission spectra at different temperatures (25°C–200 °C) were measured using different excitation wavelengths varying from 920 nm to 1030 nm in order to understand the behaviour of Stokes and anti-Stokes emission in all the glass-ceramics. The influence of ytterbium content is studied and found to substantially affect the PL emission and quantum yield and thus affect the cooling/heating characteristics. The highest intensity of anti-Stokes emission from the GC samples was observed in the composition containing 1.5 mol % or 2.0 mol % of Yb3+. Experiments monitoring the sample temperature at varying excitation wavelength between 1020 and 1030 nm demonstrates that the 1.5 mol % or 2.0 mol % Yb3+ concentrations are the most suitable for laser cooling applications.

Effective antimicrobial activity of ZnO and Yb-doped ZnO nanoparticles against Staphylococcus aureus and Escherichia coli

Nanostructured Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders were prepared by the solution method using polyvinyl alcohol (PVA) and sucrose. The effect of the ytterbium doping content on the structural, morphological, optical and antimicrobial properties was analyzed. X-ray diffraction (XRD) analysis revealed that the hexagonal wurtzite structure was retained, and no secondary phases due to doping were observed. The crystallite size was under 20 nm for all the Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders. The optical band gap was calculated, and the results revealed that this value increased with the ytterbium content, and the Eg values varied from 3.06 to 3.10 eV. The surface chemistry of the powders was analyzed using X-ray photoelectron spectroscopy (XPS), and the results confirmed the oxidation state of ytterbium as 3+ for all the samples. Zn1-xYbxO (0.0 ≤ x ≤ 0.1) nanoparticles were tested as antimicrobial agents against Staphylococcus aureus and Escherichia coli, resulting in a potential antimicrobial effect at most of the tested concentrations. These results were used in an artificial neural network (ANN). The results showed that it is possible to generate a model capable of forecasting the absorbance with good precision (error of 1–2%).

The effect of Yb doping on ZnO thin films obtained via a low-temperature spin coating method

The spin coating method was employed to fabricate Yb-doped ZnO thin films at 0, 3, 5, 7, and 9 at.% over a glass substrate at low temperature. X-ray diffraction analysis revealed that the hexagonal wurtzite structure was retained even at high doping contents. With the incorporation of Yb+3 ions, a slight decrease in the lattice parameters and crystallite size was observed as the ytterbium content increased. X-ray photoelectron spectroscopy confirmed the presence of ytterbium in the doped ZnO films, and the oxidation state of ytterbium was 3+ for all the samples. Morphological studies revealed a surface microstructure formed by micro islands, which tended to be denser as the ytterbium content increased. Optical transmittance was observed at approximately 75–85%, a blueshift was observed, and consequently, an increase in the bandgap, which varies from 3.0 to 3.2 eV, was observed. The refractive index and extinction coefficient decreased as the ytterbium dopant concentration increased. The photoluminescence results exhibited a strong ultraviolet emission, allowing the use of these thin films in optoelectronic applications.

Thermal Stability of the Structure and Mechanical Properties of Fine-Grained Aluminum Conductor Alloys Al–Mg–Zr–Sc(Yb)

The thermal stability of a fine-grained aluminum wire made of Al–Mg–Zr–Sc(Yb) alloys with different zirconium and scandium (ytterbium) contents is studied. Samples are produced by induction casting and subsequent cold working by drawing. The structure and properties of fine-grained the Al–0.6Mg–Zr–Sc alloys are shown to exhibit high thermal stability due to preliminary (before drawing) annealing at 320°C for 2 h, resulting in the precipitation of intermetallic Al3(ScxZr1 – x) particles. A fine-grained homogeneous structure with an average grain size of 2.4–2.8 μm and a microhardness of 405–440 MPa is found to be retained in the Al–0.6Mg–Zr–Sc alloys after prolonged annealing at 400°C for 100 h. A fine-grained magnesium-free Al–0.33Zr–0.16Yb ytterbium alloy has a low hardness and low thermal stability. The average grain size in it after annealing at 400°C for 100 h is 4.1–4.8 μm.

Structural, morphological, vibrational, and impedance properties of ytterbium modified bismuth titanate

Polycrystalline ytterbium modified bismuth titanate Bi4-xYbxTi3O12(x = 0, 0.1, 0.2, and 0.3) solid solutions have been synthesized using a solid state reaction method. The effect of varying the ytterbium content on the structural, morphological, vibrational, and impedance properties of this ceramic have been investigated. According to the experimental results obtained from scanning electron microscopy combined with energy dispersive X-ray analysis, a highly dense grain structure and a randomly oriented plate-like morphology were observed, showing an increase in the material grain size with Yb content. Besides, all the samples were found to be free from any other secondary phase. By means of Raman spectroscopy, it was observed that (Bi2O2)2+ layers remain unaffected with composition variation. These observations prove that Yb3+ substitution for Bi3+ occur predominantly, not only in pseudo-perovskite (Bi2Ti3O12)2- sites, but also in (Bi2O2)2+ layers, leading to cationic disorder and to a decrease in the TiO6 octahedral distortion. Raman measurements show also that all compounds exhibit a perovskite-type orthorhombic structure. This latter result is consistent with Fourier transform infra red analysis, which shows the appearance of two absorption bands below 830 cm−1. The optical band gap obtained from UV–visible spectroscopy has been found to slightly decrease from 3.1 to 3.04 eV with increasing Yb3+ substitution from x = 0 to x = 0.3, respectively. The thermal stability was also investigated. It was found from the differential scanning calorimetry that the Curie temperature (Tc) shifted backwards with increasing Yb content. No significant weight loss was found in the thermo-gravimetric analysis curve up to 800 °C temperature. Besides, the impedance spectroscopy studies show a non-Debye-type relaxation and a relaxation frequency shift to higher side with the increase in temperature. The Nyquist plot shows overlapping semicircles which indicate the existence of both grain and grain boundary effect in the prepared ceramic.

Spectroluminescent properties of ytterbium-activated fluorophosphate glasses

In this work, we studied the effect of the concentration of ytterbium ions on the spectroluminescent properties and laser parameters of fluorophosphate glasses of the Ba(PO3)2–MgCaSrBaAl2F14 system. It was shown that the absorption peak corresponds to λp=974 nm, and the stimulated emission peak is located at λ0=1002 nm. It was established that the position of these peaks does not change with an increase in the ytterbium content. The highest values of the stimulated emission cross-section σemi=0.562×10−20 cm2 and the luminescence lifetime τexp=2.1 ms correspond to the YbF3 concentration of 0.5 mol. %. The quantum yield Q for the YbF3 concentration of 0.5 mol. % is 91.6%. The presented glasses have a long luminescence lifetime, and the calculations show the possibility of obtaining large values of gain G.

The effect of annealing and ytterbium concentration on crystal structure and photoluminescence of Y3Al5O12:Yb nanopowders

Ytterbium-doped nanocrystalline powders of yttrium aluminum garnet (YAG:Yb3+) with ytterbium content from 5 to 30 at.% have been prepared by the citrate sol–gel method. Phase composition, crystal structure and microstructure of the materials were studied by means of X-ray powder diffraction techniques using both laboratory and synchrotron radiation sources. The photoluminescence spectra and the photoluminescence decay kinetics of Yb3+ ions at room temperature were performed as well. It was revealed that materials calcined at lower (1000 °C) temperature possess a small amount of Yb3+ ions occupying the octahedral sites of Al3+ ions, whereas the materials calcined at 1200 °C form the proper (Y1−xYbx)3Al5O12 solid solution.

New doubly doped cerium oxide Ce1-x-yYbyPdxO2-δ: The effect of ytterbium doping on stabilization of reduced palladium species on doped ceria oxide

Abstract The doubly and mono doped nanocrystalline mixed oxides Ce1-x-yYbyPdxO2-δ (y up to 0.4, x up to 0.2) were synthesized with the reversed microemulsion method. The morphology, microstructure and composition of the samples were investigated by TEM, EDS, XRD, XAFS, and DFT calculations of XANES spectra. The main aim of the study was the determination of the influence of an additional ytterbium content on structural and electronic properties of the Pd-doped ceria mixed oxide, i.e., the comparative discussion of the results obtained for Ce1-xPdxO2-δ and Ce1-x-yYbyPdxO2-δ. All samples were homogeneous fluorite-type nanocrystallites with very small size (3–5 nm). Reducibility studies revealed strong hydrogen consumption in these systems at low temperatures without any changes of their structure. The XANES and EXAFS spectra for Ce1-x-yYbyPdxO2-δ indicate a partial reduction of palladium at 200 °C and almost complete (90%) at 500 °C in hydrogen. The presence of ytterbium in Ce1-x-yYbyPdxO2-δ prevents the formation of metallic particles in reducing atmosphere (up to 500 °C) and strongly inhibits crystal growth of the mixed oxide.

Estimation of Sc3+ solubility in dodecahedral and octahedral sites in YSAG:Yb

AbstractA method for synthesizing YSAG:Yb optical ceramics has been developed. Additionally, the phase composition and unit cell parameters for YSAG, YbSAG, and their solid solutions have been determined. The limits of scandium solubility in the dodecahedral and octahedral sites of garnet crystal lattice have been estimated after annealing at 1600°C. The scandium solubility limit in the dodecahedral sites of YSAG:Yb was found to be 66 ± 2 at.%. The limit of scandium solubility in octahedral sites depended upon the type of garnet‐forming cations. The solubility limit for Sc3+ decreased from 97.5 ± 0.5 to 68.5 ± 1 at.% with simultaneous increase of ytterbium content in the YSAG‐YbSAG system. Therefore, the region of solid solutions existing with a garnet structure in the Al2O3–Sc2O3–Yb2O3–Y2O3 system was determined. Samples having scandium in both dodecahedral and octahedral sites, which had a Sc3+ content of ~30 at.%, were synthesized as a precursor for optical ceramic production.

Yb3+-activated optical fibers with a core fabricated by sintering powders with vibration mixing of the melt

Using sintering of powders in combination with vibration mixing of the melt, glasses for cores of preforms of optical fibers of the composition SiO2-Al2O3-P2O5-Yb2O3 with a rather high (up to 0.5 at. %) ytterbium content were fabricated. Lasing on ytterbium ions was obtained in light guides with a core of these glasses. To increase the lasing efficiency, further optimization of the process parameters is required to reduce optical losses. It is shown that one of the causes of optical losses is the inhomogeneity of the glass microstructure at the nanoscale level and the formation of nanocrystalline inclusions, which are SiO2, YbP3O9, and YbPO4.