Er 2O3 Research Articles

Luminescence features of Ho3+ , Er3+ and Tm3+ ions in red lead added non-conventional antimony oxide glass system.

In this study, a glass system based on heavy metal oxides, namely Pb3 O4 -Sb2 O3 -SiO2 , was prepared with Ho2 O3 , Er2 O3 , and Tm2 O3 as dopants. The prepared glass were characterized using X-ray diffraction (XRD) and infrared (IR) studies. The luminescence efficiencies of the three rare earth ions viz., Ho3+ , Er3+ , and Tm3+ in the glass system were investigated, specifically focusing on green (Ho3+ , Er3+ ), blue (Tm3+ ), and near-infrared (NIR) emissions. The optical absorption (OA) and photoluminescence (PL) spectra of RE mixed glass displayed strong bands in the visible and NIR regions, which were analyzed using the Judd-Ofelt (J-O) theory. The J-O coefficients (Ωλ ) were found to be in the order of Ω2 > Ω4 > Ω6 for all the three glass. Notably, the Tm3+ -doped glass exhibited the lowest Ω2 value, which was attributed to a larger degree of disorder in the glass network due to lower fractions of Sb5+ and Pb4+ ions that take part in the glass network forming. This conclusion was arrived based on the IR studies. Furthermore, the quantitative analysis of PL spectra and decay curves indicated that SbHo and SbEr glass were suitable for efficient green emission, while SbTm glass is a promising choice for blue laser emission.

Spin-Selective Coupling in Mott-Schottky Er2 O3 -Co Boosts Electrocatalytic Oxygen Reduction.

Alkaline oxygen reduction reaction (ORR) is critical to electrochemical energy conversion technology, yet the rational breaking of thermodynamic inhibition for ORR through spin regulation remains a challenge. Herein, a Mott-Schottky catalyst consisting of Er2 O3 -Co particles uniformly implanted into carbon nanofibers (Er2 O3 -Co/CNF) is designed for enhancing ORR via spin-selective coupling. The optimized Er2 O3 -Co/CNF affords a high half-wave potential (0.835V vs reversible hydrogen electrode, RHE) and onset potential (0.989 VRHE ) for the ORR surpassing individual Co/CNF and Er2 O3 /CNF. Theoretical calculations reveal the introduction of Er2 O3 optimizes the electronic structure of Co through Er(4f)-O(2p)-Co(3d) gradient orbital coupling, resulting in significantly enhanced ORR performance. Through gradient orbital coupling, the induced spin-up hole in Co 3d states endows the Er-O-Co unit active site with a spin-selective coupling channel for electron transition. This favors the decrease of the energy gap in the potential-limiting step, thus achieving a high theoretical limiting potential of 0.77 VRHE for the Er2 O3 -Co. Moreover, the potential practicability of Er2 O3 -Co/CNF as an air-cathode is also demonstrated in Zn-air batteries. This work is believed to provide, new perspectives for the design of efficient ORR electrocatalysts by engineering spin-selective coupling induced by rare-earth oxides.

A Monolayer MoS2 FET with an EOT of 1.1nm Achieved by the Direct Formation of a High-κ Er2 O3 Insulator Through Thermal Evaporation.

Achieving the direct growth of an ultrathin gate insulator with high uniformity and high quality on monolayer transition metal dichalcogenides (TMDCs) remains a challenge due to the chemically inert surface of TMDCs. Although the main solution for this challenge is utilizing buffer layers before oxide is deposited on the atomic layer, this method drastically degrades the total capacitance of the gate stack. In this work, weconstructed a novel direct high-κ Er2 O3 deposition system based on thermal evaporation in a differential-pressure-type chamber. A uniform Er2 O3 layer with an equivalent oxide thickness of 1.1nm wasachieved as the gate insulator for top-gated MoS2 field-effect transistors (FETs). The top gate Er2 O3 insulator without the buffer layer on MoS2 exhibited a high dielectric constant that reached 18.0, which is comparable to that of bulk Er2 O3 and is the highest among thin insulators (< 10nm) on TMDCs to date. Furthermore, the Er2 O3 /MoS2 interface (Dit ≈ 6 × 1011 cm-2 eV-1 ) is confirmed to be clean and is comparable with that of the h-BN/MoS2 heterostructure. These results prove that high-quality dielectric properties with retained interface quality can be achieved by this novel deposition technique, facilitating the future development of 2D electronics.

Optical analysis of RE3+ (RE = Nd or Er):B2 O3 -P2 O5 -CaF2 -ZnO-(Li2 O/Na2 O/K2 O) glasses.

Calcium boro fluoro zinc phosphate glasses modified using alkali oxide and doped with Nd3+ and Er3+ ions with the chemical composition of 69.5 (B2 O3 ) + 10 (P2 O5 ) + 10 (CaF2 ) + 5 (ZnO) + 5 (Na2 O/Li2 O/K2 O) + 0.5 (Er2 O3 /Nd2 O3 ) were prepared using a conventional melt quenching technique. The results of X-ray diffraction patterns indicated the amorphous nature of all the prepared glasses. The visible-near-infrared red (NIR) absorption spectra of these glasses were analyzed systematically. The NIR emission spectra of Er3+ and Nd3+ :calcium boro fluoro zinc phosphate glasses showed prominent emission bands at 1536 nm (4 I13/2 →4 I15/2 ) and 1069 nm (4 F3/2 →4 I11/2 ) respectively with λexci = 514.5nm (Ar+ laser) as the excitation source.

Structural, nonlinear electrical characteristics, and stability against DC-accelerated aging stress behavior of Er-doped 20 nm ZnO-Bi2 O3 -Mn2 O3 -based varistors.

In this research, ZnO-Bi2 O3 -Mn2 O3 varistors manufactured from 20 nm ZnO powder and doped with different amounts of Er2 O3 were fabricated via the conventional ceramic processing method. The effect of various Er2 O3 concentrations (0.5-2.0mol%) on the sintered density, structural improvement, and nonlinear behavior of the 20 nm ZnO-Bi2 O3 -Mn2 O3 varistors was discussed. Different Er2 O3 concentrations exerted considerable influence on the varistors. The addition of large amounts of Er2 O3 led to the inhibition of grain growth by increasing the amount of the Er2 O3 -rich spinel phase. X-ray diffraction analysis showed that the addition of Er2 O3 to the varistor systems led to the development of Er2 O3 -rich phases during sintering. During sintering, the considerable surface area of the nanoparticle powder resulted in numerous interactions in the surfaces of the ceramics manufactured from 20 nm ZnO powder. The electrical behaviors of the varistors were substantially influenced by Er2 O3 . E1 mA evidently increased from 2,144.7 to 5,482.2V/mm with the increment in doping amount. The nonlinear coefficient also dramatically increased with the increase in Er2 O3 content. The ZnO nanoparticle-Bi2 O3 -Mn2 O3 varistors doped with 1.0-2.0mol% Er2 O3 possessed high voltage and nonlinearity and were stable against DC-accelerated aging stress.

Preparation of Er2O3 and TiO2 Multilayer Films as Optical Filter Using Magnetron Sputtering Deposition

Dispersion relations of refractive indexes and extinction coefficients of constituent materials were obtained by comparing the experimental and simulated transmission spectra of single-layer Er2O3 and TiO2 films. We designed multilayer thin films of [Er2O3/TiO2]6/[Er2 O3]2/[TiO2/Er2O3]6 such that they can act as photonic crystals exhibiting a resonance wavelength of 514 nm. We prepared single-layer TiO2 and Er2O3 thin films on quartz glass substrates by employing a magnetron sputtering deposition method. Uniform films exhibiting very high transmittance values were obtained. Deposition rates of the TiO2 and Er2O3 films were 0.44 and 0.82 nm/s, respectively. [Er2O3/TiO2]6/[Er2 O3]2/[TiO2/Er2O3]6 multilayer films, to be used for optical bandpass filter applications, were also prepared using a multitarget sputtering deposition method. Uniform and transparent films were obtained; however, the wavelength corresponding to the highest transmittance was observed around 490 nm through ultraviolet-visible near-infrared spectroscopic measurements. The shift in the wavelength can be attributed to the low crystallinity and variations in the thicknesses of Er2O3 and TiO2 films.

Infrared absorption spectra of Er3+-doped Al2O3 nanopowders by the sol-gel method

The Er3+-doped Al2O3 nanopowders have been prepared by the sol-gel method, using the aluminium isopropoxide [Al(OC3H7)3]-derived γ-AlOOH sols with addition of the erbium nitrate [Er(NO3)3·5H2O]. The five phases of γ-(Al,Er)2O3, θ-(Al,Er)2O3, α-(Al,Er)2O3, ErAlO3, and Al10Er6O24 were detected with the 0–20 mol% Er3+-doped Al2O3 nanopowders at the different sintering temperature of 600–1200°C. The average grain size was increased from about 5 to 62 nm for phase transformation of undoped γ-Al2O3→α-Al2O3 at the sintering temperature from 600 to 1200°C. At the same sintering temperature, average grain size was decreased with increase of the Er3+ doping concentration. Infrared absorption spectra of γ-Al2O3 and θ-Al2O3 nanopowders showed the two broad bands of 830–870 and 550–600 cm−1, the three broad bands of 830–870, 750–760, and 550–600 cm−1, respectively. The infrared absorption spectra for the α-Al2O3 nanopowder showed three characteristic bands, 640, 602, and 453 cm−1. The two characteristic bands of 669 and 418 cm−1 for Er2O3 clusters were observed for the Er3+-doped Al2O3 nanopowders when Er3+ doping concentration was increased up to 2 mol%. The 796, 788, 725, 692, 688, 669, 586, 509, 459, and 418 cm−1 are the characteristic bands of Al10Er6O24 phase.

Comparison of the Burnup Characteristics and Radiotoxicity Hazards of Rock-like Oxide Fuel with Different Types of Additives

Burnup characteristics of rock-like oxide (PuO2-ZrO2: ROX) fueled LWR have been studied with an additive ThO2, UO2 or Er2O3. A ROX fueled LWR core has reactivity coefficients and burnup reactivity swing problems, which can be mitigated by these additives. From the burnup calculations of the ROX fueled LWR, it was found that the additive ThO2 causes a few percent decrease in Pu transmutation in ROX fuel, while the additive UO2 or Er2O3 decreases it largely. The production of 241 Am, which is a parent of long-lived 237Np, is smaller in ThO2 added fuel than that in UO2 or Er2O3 added fuel. However, the productions of 243Am and 244Cm are more in ThO2 added fuel than those in UO2 or Er2O3 added fuel. The long-lived fission products (LLFPs) production in ThO2 added fuel is nearly the same as that in UO2 added fuel, and smaller than that in Er2 O3 added fuel. As a result of these Pu transmutation and minor actinides (MAs) and LLFPs productions, ingestion radiotoxicity hazard index of ThO2 added ROX spent fuel is lower than that of UO2 or Er2O3 added ROX spent fuel, except at the 105 years cooling. From these calculations, ThO2 is recommended to be used as the additive in ROX fuel.