Effect Of Doping Concentration Research Articles

Facile fabrication of novel europium doped strontium yttrate (SrY2O4:Eu3+) electrospun nanofibers for flexible display applications

Novel europium doped strontium yttrate (SrY 2 O 4: Eu 3+ ) nanofibers have been firstly synthesized by electrospinning. SrY 2 O 4: Eu 3+ nanofibers have been systematically examined at different calcination temperatures. The TGA study reveals the thermal behaviour of SrY 2 O 4: Eu 3+ nanofibers which stabilises at 900⁰C. SrY 2 O 4: Eu 3+ nanofibers have an average diameter of 328 nm before calcination and 162 nm post calcination. X-ray diffraction (XRD) spectra of SrY 2 O 4: Eu 3+ nanofibers revealed the orthorhombic phase with Pnam space group. The ionic radii and charge compensation have significant effect on the XRD and photoluminescence (PL) spectra of SrY 2 O 4: Eu 3+ nanofibers. PL spectra was observed under 395 nm excitation and a strong emission line spotted at 612 nm is attributed to characteristic electric dipole transition 5 D 0 → 7 F 2 of Eu 3+ ion. Effect of dopant concentration on PL of host SrY 2 O 4: Eu 3+ nanofibers have also been explored. SrY 2 O 4 nanofibers doped with 10 mol% of Eu 3+ ions exhibit optimum emission intensity while concentration quenching is observed for higher dopant concentration. The SrY 2 O 4: Eu 3+ nanofibers show affirmative agreement with SrY 2 O 4: Eu 3+ bulk counterpart. The CIE coordinates for SrY 2 O 4: Eu 3+ nanofibers appear in red region with good colour purity. SrY 2 O 4: Eu 3+ nanofibers possess inherent luminescence property which makes it potential candidate for flexible display applications. • Fabrication of novel SrY 2 O 4: Eu 3+ nanofibers first time by electrospinning technique • SrY 2 O 4: Eu 3+ nanofibers manifest uniform continuity with an average diameter 162 nm • SrY 2 O 4: Eu 3+ nanofibers manifest remarkable emission in red region upon UV excitation • Ionic radii and charge compensation lead to substitution of Y 3+ ions by Eu 3+ ions • SrY 2 O 4: Eu 3+ nanofibers exhibit intrinsic luminescence property within fiber itself for flexible display application.

Edge-TCT evaluation of high voltage-CMOS test structures with unprecedented breakdown voltage for high radiation tolerance

This paper presents the edge Transient Current Technique (eTCT) measurements of passive test-structures on the UKRI-MPW0 pixel chip, a 280 µm thick proof-of-concept High Voltage-CMOS (HV-CMOS) device designed and fabricated in the LFoundry 150 nm technology node with a nominal substrate resistivity of 1.9 kΩ cm. Samples were irradiated up to 1 × 1016 1 MeV neq cm−2 with neutrons to observe the change in depletion depth and effective doping concentration with irradiation. A depletion depth of the sensor was found to be ≈50 µm at ≈−400 V at 1 × 1016 1 MeV neq cm−2. A stable damage introduction rate (g c ) was also calculated to be 0.011 ± 0.002 cm−1.

Chemical Bath Deposition Grown Zno Thin Films: Role of Manganese Doping

In this study, the effect of Mn doping concentration on the structural, microstructural, linear and nonlinear optical properties of ZnO was investigated. Pristine and Mn-doped ZnO films were prepared by chemical bath deposition on a glass substrate. The crystal structure and surface morphology of the films were determined by X-ray diffraction and force electron scanning microscopy (FESEM). X-Ray Diffraction (XRD) analysis revealed that the films had a polycrystalline structure and all films were ZnO with a hexagonal structure. In addition, a shift was detected in the XRD pattern of the films with the Mn doping process. According to the FESEM results, the surface of the films has irregularly shaped particles. Linear and nonlinear optical parameters were estimated using transmittance and absorbance measurements. And then, optical absorption coefficient, extinction coefficient, refractive index, optical dielectric constants, surface, and volume energy loss functions, optical band gap values, and optical and electrical conductivity were determined as linear optical properties. It was determined that these properties were affected by Mn-doped ratios. It was determined that nonlinear optical properties such as linear optical properties were also affected by the doping process.

X-ray detectors based on CsPb1-xSrxBr3 thick films

The CsPbX3 perovskites have demonstrated promising applications in the field of X-ray detection. Appropriate element doping to substitute Pb in CsPbX3 not only improves the photoresponse performance of the resulting material but also reduces the Pb content for achieving environmental protection. Herein, X-ray detectors based on Sr-doped CsPb1-xSrxBr3 thick films were developed. The effects of Sr doping concentration were investigated. The incorporation of Sr increased the density of the CsPbBr3 thick film and modulated the bandgap of the materials. CsPb1-xSrxBr3 exhibited good optical responses at different bias voltages and X-ray doses. The X-ray response improved as the Sr-doping concentration increased. Therefore, the partial substitution of Sr into CsPbBr3 is suitable for reducing the Pb content in X-ray detectors. Furthermore, the development of CsPb1-xSrxBr3 thick films provides a new strategy for the detection of X-rays.

Low-cost Zn2(OH)BO3:Pb2+ phosphor for large-scale thermometric applications

A relatively low-cost blue-emitting Zn2(OH)BO3:Pb2+ crystalline powder phosphor was successfully synthesized through the hydrothermal method in a one-pot synthesis route at low temperature. The effects of dopant concentration on the structural and optical properties of Zn2–2x(OH)BO3:Pb2x (0 ≤ x ≤ 0.100) were studied. A crystal degradation and luminescence quenching occurred with dopant concentration above 1.5% mol. The synthesized phosphor had a broadband emission that peaked at 423 nm when excited with 289 nm light. While the absorption edge of the samples exhibits a redshift, the luminescence bands were not considerably changed with Pb2+ doping concentration. The optical temperature sensing capability of Zn2(OH)BO3:Pb2+ was evaluated by temperature-dependent luminescence measurements in the range of 303 – 423 K. The highest relative temperature sensitivities based on luminescence intensity and lifetime were obtained as 2.45% K−1 at 373 K and 3.04% K−1 at 403 K, respectively. A temperature gradient visualization on a surface was demonstrated using Zn2(OH)BO3:Pb2+ coating. The obtained results show that Zn2(OH)BO3:Pb2+ phosphors are a good candidate for temperature sensing on large-scale areas, covering the temperature range from 303 K to 423 K.

Development of surface-modified galvanised steel as an immobilised photocatalyst for textile wastewater treatment

The quest for cost-effective photocatalytic material and a simple process for wastewater degradation has inspired the development of immobilised ZnO photocatalyst by surface-modifying the commercial galvanised steel via plasma electrolytic oxidation process (PEO). In this work, galvanised steel underwent oxidation via PEO using a suitable base electrolyte system (borax and sodium aluminate). The optimum time for effectively converting zinc in the galvanised steel to ZnO is investigated. The 90 s PEO process effectively converted ZnO with the bandgap value of 3.30 eV. Additionally, vanadium was doped into the ZnO by adding sodium metavanadate (0.3 to 1.2 g/L) to the base electrolyte to reduce the bandgap. The effect of dopant concentration on the surface morphology, phase analysis, optical properties, recombination rate and separation efficiency of charge carriers were investigated. Also, the photocatalytic efficiency was measured by evaluating methylene blue dye's degradation under UV light irradiation. It was found that 0.9 g/L of sodium meta vanadate addition to the base electrolyte system was shown crystalline ZnO with near-visible light absorption (3.15 eV) along with reduced electron-hole recombination. Finally, the vanadium-doped ZnO photocatalyst showed 95 % MB dye degradation with a rate constant K = 0.014 min−1 under UV light.

Silicon Detectors for the LHC Phase-II Upgrade and Beyond – RD50 Status Report

A large R&D program has been underway to develop silicon sensors with sufficient radiation tolerance for LHC-Phase-II trackers and the next generation of collision experiments. Key areas of recent RD50 research include new technologies such as CMOS and Low Gain Avalanche Detectors (LGADs), where a dedicated multiplication layer to create a high field region is built into the sensor. We also seek for a deeper understanding of the connection between macroscopic sensor properties such as radiation-induced increase of leakage current, effective doping concentration and trapping, and the microscopic properties at the defect level. Another strong activity is the development of advanced sensor types, like 3D silicon detectors. We will present the state of the art in silicon detectors at radiation levels corresponding to LHC-Phase-II fluences and beyond. Based on our results, we will give an outlook towards the silicon detectors to be used for particle detectors at future colliders like the FCC.

Photocatalytic activation of Ag-doped SrSnO3 nanorods under visible light for reduction of p-nitrophenol and methylene blue mineralization

The utilization of solar energy for the treatment of wastewater pollutants by photocatalysts has been considered a promising solution to address environmental problems. Herein, we have synthesized silver nanoparticle-doped strontium stannate (Ag-doped SrSnO3) nanorods by hydrothermal method followed by ultrasonic treatment. The developed nanocomposites were applied for photocatalytic reduction of p-nitrophenol (4-NP) and methylene blue (MB) mineralization under visible light illumination. The effect of hydrothermal duration time (16–25) h, Cetyltrimethylammonium bromide (CTAB) and silver nanoparticles (Ag NPs) concentration (0.5–2.5) wt% on the crystal, surface, optical, photoluminescence as well as photocatalytic activity were studied. A well-defined crystalline cubic phase of SrSnO3 was obtained. CTAB inhibits the crystal growth of SrSnO3. Reduction of 4-NP and MB mineralization were used as two-model reactions for testing the effect of Ag doping concentration on the photocatalytic activities of Ag/SrSnO3 under visible light illumination. The obtained results show that 2.0 wt% of Ag-doped SrSnO3 exhibits efficient photocatalytic reduction of 4-NP with 98.2% conversion within 5 min of reaction time. Also, 87% of the MB sample was mineralized after 1 h of visible illumination using 2.0% Ag/SrSnO3 in the presence of H2O2. Besides, we have discussed the possible photocatalytic mechanism for reduction of 4-NP and mineralization of MB using 2.0 wt% of Ag doped SrSnO3 under visible light illumination.

4H-SiC p-i-n Low-Energy X-Ray Detectors With P-Layer Formed by Al Implantation

The results of electrical characterization and X-ray detection measurement of 4H-SiC p-i-n diodes with the p-layer formed by Al implantation are reported. From the capacitance-voltage measurement, the effective doping concentration of the 4H-SiC epitaxial layer is determined to be <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.88\times 10^{14}$ </tex-math></inline-formula> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> . The detectors exhibited a consistently low leakage current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 6$ </tex-math></inline-formula> pA at −150 V, indicating excellent reverse blocking properties of the p-n junction formed by Al implantation. The measured full width at half maximum (FWHM) of the 59.5 keV gamma-ray peak is ~4.2 keV, corresponding to an energy resolution of 7%. In addition, the characteristic X-rays emitted from the V, Mn, Fe, Ni, Ge, Y, and Mo targets are detected by reducing the noise limit in the preamplifier. The linearity error between the peak channel and the featured <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K\alpha $ </tex-math></inline-formula> line energy is within 0.02%. The detector demonstrates an FWHM of 1.76 ± 0.1 keV at 4.9 keV and 1.67 ± 0.05 keV at 17.5 keV. The obtained results show that the SiC p-i-n diodes with p-layer formed by Al implantation can be used as promising low-energy X-ray detectors with reasonable resolution.

Microscopic origin of the acceptor removal in neutron-irradiated Si detectors - An atomistic simulation study

The improved radiation hardness of p-type Si detectors is hindered by the radiation-induced acceptor removal process, which is not fully understood yet. Through atomistic modeling of displacement damage and dopant interactions, we analyze the acceptor removal under neutron irradiation, providing physical insight into its microscopic origin. Our results show that the fast decay of the effective dopant concentration (Neff) at low irradiation fluences is due to B deactivation caused by Si self-interstitials. The intriguing increase of the acceptor removal parameter with the initial dopant concentration (Neff,0) is explained by the limited number of mobile Si self-interstitials that survive annihilation and clustering processes. The sublinear dependence of the removal parameter on Neff,0 is associated to the inhomogeneity of damage for low Neff,0 and the formation of B-interstitial clusters with several B atoms for high Neff,0. The presence of O and C modifies B deactivation mechanisms due to the key role of BiO defects and the trapping of vacancies and Si self-interstitials, but for the impurity concentrations analyzed in this work ([O] >> [C]) it has little effect on the overall amount of removed acceptors. At high irradiation fluences, the reported increase of Neff is attributed to the formation of defect-related deep acceptors. From the analysis of the defect concentrations resulting from neutron irradiation and the occupancy of small clusters with acceptor levels reported in literature, we point out the tetra-vacancy cluster as one of the main contributors to Neff with negative space charge.

The effect of magnesium doping concentration on the structural and optical properties of zinc oxide nanoparticles

In this study, the optical and structural properties of Magnesium doped Zinc Oxide (Zn1-xMgxO) nanoparticles (x = 1%, 3%, and 5%) were examined. The synthesis was carried out at 300 oC by using a simple co-precipitation method. The structural samples were used to characterize the synthesized nanoparticles by using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Energy Dispersive X-Ray spectroscopy (EDX) was used to determine the chemical composition of the samples. Furthermore, UV-Vis spectroscopy was conducted to study our samples’ optical characteristics. As per XRD analysis, both pure and Mg doped ZnO samples possess wurtzite structure. The particle size was revealed to decrease significantly with Mg concentration, from 36 nm for pure sample to 23.87 nm with 5% Mg. In comparison to ZnO, the XRD pattern of Mg-doped ZnO shows a peak shift towards lower 2θ values. As a result of deformation of crystal structure caused by integrated Mg+2 ions onto Zn+2 sites. SEM images of synthesized samples reveal that the nanoparticles possess sheet, spherical and rod like morphologies for different values of x. The EDX analysis verifies the purity of samples within the detection limits. According to optical absorption spectra obtained from UV-Visible spectroscopy in the 200nm to 1000nm range affirmed that as Mg concentration increased, the band gap increased from 3.37 eV for pure sample to 3.74 eV with 5% Mg. The UV-Visible spectra of pure ZnO and Mg-doped ZnO samples also exhibit distinct peaks in the UV region at 335 nm, 311 nm, 310.6 nm, and 310 nm. Across the spectra of pure and Mg-doped ZnO samples, the UV peak is attributed to free exciton transitions, whereas, in the spectra of Mg-doped ZnO UV absorbance peak in the visible region is attributed to the radiative transitions of electrons captured at oxygen vacant sites with holes trapped at singly ionized oxygen vacancies.

Impact of Co2+ on the magneto-optical response of MAPbBr3: An inspective study of doping and quantum confinement effect

The current work establishes the excitonic magneto-optic (M − O) effects of magnetic circular dichroism (MCD) in Cobalt (Co2+) doped diamagnetic organic−inorganic hybrid CH3NH3PbBr3 perovskites at low magnetic field and room temperature. The solution-processed perovskites are prepared in the form of single crystal thin films and quantum dots. The structural studies confirm the successful doping of the Co2+ in the perovskite lattice. Further, the perovskites are investigated as diluted magnetic semiconductors (DMSs) related to the dopant concentration effect and the size effect on their M − O properties. Magnetic dopant Cobalt leads to the strong sp-d exchange coupling that generates higher values of Zeeman splitting (ΔEZ) than the pristine MAPbBr3 due to the excitonic 1s Pb–Br absorption quantified by analysis of MCD. The ΔEZ value increases with the Co concentration up to 10 mol % and then starts decreasing. This concentration dependency can be linked with the luminescence of the perovskites with the Co2+ doping. The rise and fall of the MO and PL properties can be defined by the formation of Co–Co pairs in heavily doped perovskites which can influence the spin conditions of the paramagnetic Co ions. Using the Kramers–Kronig relations with MCD, the calculated Verdet constant exhibits a massive increase in value with the doping of cobalt, much higher than the industry standard Faraday rotator indicating their probable usability in this industry. Further in the quantum dots, the quantum confinement effect is pronounced that increases the MCD and hence the ΔEZ multiple times higher than the bulk perovskite films. These results provide a promising pathway for the study of solution-processed hybrid perovskites as DMSs for spintronics.

Synergetic Effect of Li-Ion Concentration and Triple Doping on Ionic Conductivity of Li7La3Zr2O12 Solid Electrolyte.

Li7La3Zr2O12 (LLZO) is a promising and safe solid electrolyte for all-solid-state batteries. To achieve high ionic conductivity of LLZO, stabilizing the cubic phase and reducing Li loss during the sintering process is essential. Therefore, reducing the sintering temperature, which increases the sintering time for high-density pellets, is necessary. Herein, we investigate the change in the crystal structure, morphology, and Li ionic conductivity of LLZO pellets by triple doping with Al, Ga, and Ta and modulating the variation in initial Li concentrations. Interestingly, the proportion of the conductive cubic phase increased with increasing Li stoichiometry by 1.1 times, and this tendency was further accelerated by triple doping. The synergetic effects of triple doping and Li concentration also minimized Li loss during sintering. Accordingly, it provided a high-quality LLZO pellet with good ionic conductivity (3.6 × 10−4 S cm−1) and high relative density (97.8%). Notably, the LLZO pellet was obtained using a very short sintering process (40 min). Considering that the most time-consuming step is the sintering process for LLZO, this study can provide guidelines for the fast production and commercialization of LLZO electrolytes with high ionic conductivity.

Effect of Re aggregation doping configurations on the thermal and mechanical properties of W-Re alloys: A molecular dynamics study

Thermal and mechanical properties of plasma facing materials (PFMs) are critical for the magnetic confinement fusion devices. In this study, by using molecular dynamics (MD) simulations, we investigate the impact of different dopant configurations and doping levels on the thermal and mechanical properties of W-Re alloys. In the studied models, Re atoms are either randomly distributed in the system, or aggregated with certain shapes (sphere, cone, cylinder, prism, and plane). Accounting for the thermal conductivity and mechanical properties (including the Elastic modulus, Poisson's ratio, and Cauchy pressures, etc.) for the models with different Re aggregation configurations and concentrations, we find that W-Re alloys with spherical Re aggregation configuration exhibit larger thermal conductivity compared with other aggregation configurations regardless of the Re concentration, which also bear good mechanical properties. Also, the thermal conductivity of the spherically doped W-Re alloys as a function of temperature were investigated. The obtained results indicate that as the temperature increases, the phonon scattering increases and the thermal conductivity of the system in general decreases. Furthermore, the normalized phonon density of states (DOS) was calculated to better understand the effect of different doping configurations and concentrations on the thermal conductivity of W-Re alloys. The results show that the model with spherical Re configuration bears a wider phonon frequency domain, indicating inelastic scattering at the W-Re interface. However, when more Re atoms aggregate, the small structural size differences between W and Re atoms are magnified. In this case, the W-Re alloy lattice showed non-negligible distortions, and the whole system exhibited anomalous lattice constants and mechanical properties. Our investigation yields new insights into the physical mechanisms governing heat transport in alloys, and provides guidance to the design of plasma facing materials in terms of thermal transport.

Distinct junction transformations of pixel-arrayed long-wavelength infrared detectors by photocurrent mapping

Pixel-arrayed long-wavelength HgCdTe is of great significance in the development of infrared detection. However, the PN junction formation process for long-wavelength HgCdTe is complex. The damage induced by boron ion implantation and subsequent low-temperature annealing may results in changes in the effective doping concentration and geometry of the actual n-type implantation region. Therefore, an in-situ, non-destructive scanning-photocurrent-microscopy (SPCM) method is needed to test the performance and electroactive defects of HgCdTe devices. Here, the pixel-arrayed long-wavelength infrared detectors with n-on-p structure formed by B+ ion implantation in Hg vacancy-doped Hg0.78Cd0.22Te crystals were fabricated. The SPCM method is used to characterize the PN junction performance of long-wavelength Hg0.78Cd0.22Te array detectors. It is found that the long-wavelength device transformed from n-on-p structure to n-on-n− structure at about 175 K, and further turns into an n−-on-n-on-n− structure with the temperature increasing. In addition, when the temperature increases, the minority carrier diffusion length in the B+ ion implantation region gradually decreases with the activation of the recombination center. Our work provides an effective theoretical and experimental basis for the HgCdTe junction formation process.

Effects of defects on magnetic properties of molybdenum doped indium oxide

Based on density functional theory, this paper systematically calculated the effects of different Mo doping concentrations and neutral intrinsic defects on the electronic structure and magnetic properties of Mo-doped In2O3 (IMO) systems. Studies have shown that the magnetic properties of the IMO system are mainly derived from the hybridization of doped Mo atoms and neighboring O atoms, and as the Mo doping concentration increase, the total magnetic moment of the IMO system also increases, and the magnetic properties increase. In the same configuration, VO, Oi, VIn, and Ini were introduced, and the magnetization energies were 107.29 meV, 2.21 meV, 0.24 meV and-703.72 meV, respectively. Except for the system containing Ini, it transformed into an antiferromagnetic ground state, Others still exhibit ferromagnetic coupling, which shows that different intrinsic defects have a regulatory effect on doping magnetism.

Effect of iron doping concentration on the structure and photocatalytic activity of ZnO nanosheets under visible light irradiation

Undoped and Fe-doped ZnO nanosheets have been successfully synthesized by hydrothermal method using zinc acetate as the source of Zn2+, iron(III) nitrate as the doping source, urea as media to control the solution pH and polyethylene glycol as structure-directing agents. The obtained materials were characterized by means of XRD, TEM, BET, FT-IR and UV-Vis-DRS. The results show that ZnO has a hexagonal wurtzite structure and that the Fe3+ ions were well incorporated into the ZnO nanosheets crystal lattice. As the Fe/Zn molar ratios increased from 0.05% to 0.1% results in increased absorption in the visible region of the spectrum, a slightly decreased optical band gap and increased photocatalytic activity in comparison with the undoped ZnO. The photocatalytic activity was evaluated based on photodegradation of methylene blue (MB) in aqueous solutions under visible light irradiation. The optimum Fe doping at the molar ratios of Fe/Zn = 0.1% showed the highest photocatalytic activity and was 2.19 times higher than that of undoped ZnO. The kinetic studies showed the decomposition of MB followed pseudo first-order kinetics with the rate constant were determined kapp = 7.33×10-2 min−1.

The physical properties of spinel cubic Co3O4 thin films prepared by a PSM

Undoped and Mn-doped Co3O4 films were deposited on heated glasses substrates (TS = 400°C) using a homemade pneumatic spray method (PSM). The solution concentration and deposition time are 0.1 M and 4 min respectively. The effect of manganese doping concentration on structural, optical and electrical properties of cobalt oxide were investigated. The elaborated films were characterized by X-ray diffraction, UV-Vis spectroscopy, atomic force microscopy (AFM) the three-dimensional (3D), energy dispersive spectroscopy (EDS), and four points probe measurements. The XRD study showed that all films were polycrystalline consisting with spinel cubic phase orientated along to (111) plane. The lattice strain and crystallite size were estimated by Williamson-Hall method. The morphology of Mn-doped Co3O4 thin films shows a homogeneous surface with straight acicular nanorods (SANRs). EDS analysis showed the presence of peaks associated with Co, O and Mn elements which confirm the composition of the thin films. The optical band gaps varies from 1.42±0.07 to 1.47±0.07 eV of Egop1and Egop2 varies from 1.87±0.10 to 2.11±0.11 eV. In addition, the electrical measurement show a maximum electrical conductivity (σ= 15.54±0.78 (Ω.cm)-1) at 6% wt of Mn.

Influence of rare earth doping and calcination temperature on temperature sensitivity of gadolinium molybdate nanoparticle

NaGd(MoO4)2: Er3+/Yb3+ up-conversion fluorescence materials was prepared by a sol-gel method. And the effects of activator ion doping concentration, sensitizer ion doping concentration and calcination temperature on the temperature sensitivity of NaGd(MoO4)2: Er3+/Yb3+ materials were studied. The samples were characterized by XRD, SEM and fluorescence spectra. The temperature sensitivity of different powder was calculated by using the temperature measurement formula of fluorescence intensity ratio. At this time, the results show that the temperature sensitivity is the highest when the concentration of Er3+ is 0.5% in the range of 0.3–2.0% and when the concentration of Yb3+ is 28% in the range of 16–32%. Under the condition of 0.5% Er3+/ 28% Yb3+, a higher value of 0.0268 K−1 can be obtained. Then, the change of temperature sensitivity with doping concentration was analyzed based on the theory of energy transition and the analysis of fluorescence lifetime. In addition, with the calcination temperature increasing from 700 ℃ to 1100 ℃, it is found that the fluorescence intensity and temperature sensitivity of the calcination temperature at 800 ℃ are both great. At the same time, the influence of doping concentration of Er3+， doping concentration of Yb3+ and calcination temperature on the sensitivity was compared. It was found that the influence of Er3+ ion doping concentration was more significant. These results indicate that Er3+ and Yb3+ co-doped NaGd(MoO4)2 powder has a great application prospect in temperature sensing.

Vacuum sintering of Yb2O3 transparent ceramics: Effect of ZrO2 concentration on structural and optical properties

• Highly transparent ytterbium oxide (Yb 2 O 3 ) ceramics were successfully prepared by vacuum sintering method using ZrO 2 as a sintering aid. • ZrO 2 was found to be an effective sintering additive that can effectively inhibit Yb 2 O 3 grain growth and promote the removal of residual pores. • The effects of ZrO 2 doping concentration on the crystal structure, microstructure, optical transmittance, and band gap of Yb 2 O 3 transparent ceramics were studied for the first time. In this study, highly transparent Yb 2 O 3 ceramics were successfully fabricated via vacuum sintering at 1800 °C for 10 h with ZrO 2 as a sintering additive. The effect of zirconia doping concentration on crystal structure, microstructure, and optical properties of Yb 2 O 3 transparent ceramics was investigated. It was found that the introduction of zirconia could effectively prohibit grain growth while promoting the removal of residual pores. The mean grain size decreased from 39.04 µm to 4.27 µm as the Zr 4+ content increased from 0 to 5 at%. The 3 at% ZrO 2 -doped Yb 2 O 3 transparent ceramics have the best optical quality, with a transmittance of 75% at 1100 nm and about 81% in the mid-infrared region. This study indicates that Yb 2 O 3 transparent ceramics with good optical properties can be obtained by properly adjusting the addition amount of ZrO 2 . On this basis, the absorption spectra, emission spectra, and fluorescence lifetime of Yb 2 O 3 transparent ceramic were investigated. High transmittance and high activation cation density make Yb 2 O 3 transparent ceramics potential candidates for thin-disk laser elements.