Topological Luminophor Y2O3:Eu3++Ag with High Electroluminescence Performance

An Improved Smart Meta-Superconductor MgB2

Increasing and improving the critical transition temperature (TC), current density (JC) and the Meissner effect (HC) of conventional superconductors are the most important problems in superconductivity research, but progress has been slow for many years. In this study, by introducing the p-n junction nanostructured electroluminescent inhomogeneous phase with a red wavelength to realize energy injection, we found the improved property of smart meta-superconductors MgB2, the critical transition temperature TC increases by 0.8 K, the current density JC increases by 37%, and the diamagnetism of the Meissner effect HC also significantly improved, compared with pure MgB2. Compared with the previous yttrium oxide inhomogeneous phase, the p-n junction has a higher luminescence intensity, a longer stable life and simpler external field requirements. The coupling between superconducting electrons and surface plasmon polaritons may be explained by this phenomenon. The realization of smart meta-superconductor by the electroluminescent inhomogeneous phase provides a new way to improve the performance of superconductors.

Critical Current Density and Meissner Effect of Smart Meta-Superconductor MgB2 and Bi(Pb)SrCaCuO

The smart meta-superconductor MgB₂ and Bi(Pb)SrCaCuO increase the superconducting transition temperature (T_C), but the changes in the transport critical current density (J_C) and Meissner effect are still unknown. Here, we investigated the J_C and Meissner effect of smart meta-superconductor MgB₂ and Bi(Pb)SrCaCuO. The use of the standard four-probe method shows that Y₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺+Ag inhomogeneous phase significantly increase the J_C, and J_C decreases to a minimum value at a higher temperature. The Meissner effect was measured by direct current magnetization. The doping of Y₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺+Ag luminescent inhomogeneous phase causes a Meissner effect of MgB₂ and Bi(Pb)SrCaCuO at a higher temperature, while the non-luminescent dopant reduces the temperature at which samples have Meissner effect. The introduction of luminescent inhomogeneous phase in conventional MgB₂ and copper oxide high-temperature Bi(Pb)SrCaCuO superconductor increases the T_C and J_C, and Meissner effect is exerted at higher temperature. Therefore, smart meta-superconductivity is suitable for conventional and copper oxide high-temperature superconductors.

Synthesis of high luminescent Eu3+ doped nanoparticle and its application as highly sensitive and selective detection of Fe3+ in real water and human blood serum

The present work reports a highly efficient Ca doped Eu: Y₂O₃ i.e Ca_0.05Eu_0.01Y_1.94O₃ (CEY.) nanophosphor material synthesized through a facile combustion method, as a simple and selective turn-off fluorescence probe for the quantitative analysis of iron ions (Fe³⁺). The proposed sensor allows the quantification of iron in the range of 10 µM-90 µM with a limit of detection (LOD) ∼ 63.2 nM under the natural pH range. Moreover, CEY nanophosphor shows an excellent fluorescence phenomenon with a gradual increase in the Fe³⁺ ion concentration. It has been observed that the corresponding PL intensity gets completely quenched with 500 µM Fe³⁺ ion concentration. Furthermore, the applicability of the sensor as an efficient probe has been investigated with real water samples, iron tablets, and human blood serum (HBS). The selectivity of the probe has also been analyzed with various metal ions and biomolecules. Thus, in turn, the as-obtained sensing probe illustrates an excellent accuracy, sensitivity, and selectivity, and offers potential application in clinical diagnosis, biological and real water sample studies, with the detection of Fe³⁺ ion. Furthermore, it does not require any acidic medium for a level-free, and non-enzymic detection of a real sample with almost not affecting the sample quality and henceforth provides more reliable results.

Reinforcing Increase of ΔTc in MgB2 Smart Meta-Superconductors by Adjusting the Concentration of Inhomogeneous Phases

Incorporating with inhomogeneous phases with high electroluminescence (EL) intensity to prepare smart meta-superconductors (SMSCs) is an effective method for increasing the superconducting transition temperature (T_c) and has been confirmed in both MgB₂ and Bi(Pb)SrCaCuO systems. However, the increase of ΔT_c (ΔT_c = T_c ‒ T_cpure) has been quite small because of the low optimal concentrations of inhomogeneous phases. In this work, three kinds of MgB₂ raw materials, namely, ^aMgB₂, ^bMgB₂, and ^cMgB₂, were prepared with particle sizes decreasing in order. Inhomogeneous phases, Y₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺/Ag, were also prepared and doped into MgB₂ to study the influence of doping concentration on the ΔT_c of MgB₂ with different particle sizes. Results show that reducing the MgB₂ particle size increases the optimal doping concentration of inhomogeneous phases, thereby increasing ΔT_c. The optimal doping concentrations for ^aMgB₂, ^bMgB₂, and ^cMgB₂ are 0.5%, 0.8%, and 1.2%, respectively. The corresponding ΔT_c values are 0.4, 0.9, and 1.2 K, respectively. This work open a new approach to reinforcing increase of ΔT_c in MgB₂ SMSCs.

Relationship between the TC of Smart Meta-Superconductor Bi(Pb)SrCaCuO and Inhomogeneous Phase Content

A smart meta-superconductor Bi(Pb)SrCaCuO (B(P)SCCO) may increase the critical transition temperature (T_C) of B(P)SCCO by electroluminescence (EL) energy injection of inhomogeneous phases. However, the increase amplitude ΔT_C (ΔTC=TC−TC,pure) of T_C is relatively small. In this study, a smart meta-superconductor B(P)SCCO with different matrix sizes was designed. Three kinds of raw materials with different particle sizes were used, and different series of Y₂O₃:Sm³⁺, Y₂O₃, Y₂O₃:Eu³⁺, and Y₂O₃:Eu³⁺+Ag-doped samples and pure B(P)SCCO were prepared. Results indicated that the T_C of the Y₂O₃ or Y₂O₃:Sm³⁺ non-luminescent dopant doping sample is lower than that of pure B(P)SCCO. However, the T_C of the Y₂O₃:Eu³⁺+Ag or Y₂O₃:Eu³⁺ luminescent inhomogeneous phase doping sample is higher than that of pure B(P)SCCO. With the decrease of the raw material particle size from 30 to 5 μm, the particle size of the B(P)SCCO superconducting matrix in the prepared samples decreases, and the doping content of the Y₂O₃:Eu³⁺+Ag or Y₂O₃:Eu³⁺ increases from 0.2% to 0.4%. Meanwhile, the increase of the inhomogeneous phase content enhances the ΔT_C. When the particle size of raw material is 5 μm, the doping concentration of the luminescent inhomogeneous phase can be increased to 0.4%. At this time, the zero-resistance temperature and onset transition temperature of the Y₂O₃:Eu³⁺+Ag doped sample are 4 and 6.3 K higher than those of pure B(P)SCCO, respectively.

A novel high efficiency and ultra-stable red emitting europium doped pyrophosphate phosphor for multifunctional applications

The RBPO:Eu3+ phosphor developed by the nonlinear optical material-inspired methodology can serve as a potential candidate in solid state lighting applications, artistic appreciation or some applications under extreme conditions.

Y2O3: Eu3+/PMMA hybrid film as a converter for enhanced harvesting of broadband solar-blind UV light

At present, the most common materials for solar-blind UV light detectors are wide band-gap semiconductors, which generally have high requirements and complex methods for preparation. Ordinary semiconductor materials such as silicon, TiO₂, and Cu₂O were industrialized, but they were excluded for direct harvest of solar-blind UV light due to their inability to absorb solar-blind light photons. Here, inorganic-organic hybrid film of Y₂O₃:Eu³⁺/PMMA was used as a spectral converter to realize the detection of broadband solar-blind UV light by ordinary semiconductor, converting broadband solar-blind UV luminescence to visible luminescence based on down-conversion process, after which the visible luminescence was detected by the Si photo-resister. The results show that hybrid film based on rare earth luminescence materials is particularly valuable for broadband solar-blind UV detection.

Thermal and Plasma-Enhanced Atomic Layer Deposition of Yttrium Oxide Films and the Properties of Water Wettability

The atomic layer deposition (ALD) of yttrium oxide (Y₂O₃) is investigated using the liquid precursor Y(EtCp)₂(iPr-amd) as the yttrium source with thermal (H₂O) and plasma-enhanced (H₂O plasma and O₂ plasma) processes, respectively. Saturation is confirmed for the growth of the Y₂O₃ films with each investigated reactant with a similar ALD window from 150 to 300 °C, albeit with a different growth rate. All of the as-deposited Y₂O₃ films are pure and smooth and have a polycrystalline cubic structure. The as-deposited Y₂O₃ films are hydrophobic with water contact angles >90°. The water contact angle gradually increased and the surface free energy gradually decreased as the film thickness increased, reaching a saturated value at a Y₂O₃ film thickness of ∼20 nm. The hydrophobicity was retained during post-ALD annealed at 500 °C in static air for 2 h. Exposure to polar and nonpolar solvents influences the Y₂O₃ water contact angle. The reported ALD process for Y₂O₃ films may find potential applications in the field of hydrophobic coatings.

Smart meta-superconductor MgB2 constructed by the dopant phase of luminescent nanocomposite

On the basis of the idea that the injecting energy will improve the conditions for the formation of Cooper pairs, a smart meta-superconductor (SMSC) was prepared by doping luminescent nanocomposite Y₂O₃:Eu³⁺/Ag in MgB₂. To improve the superconducting transition temperature (T_C) of the MgB₂-based superconductor, two types of Y₂O₃:Eu³⁺/Ag, which has the strong luminescence characteristic, with different sizes were prepared and marked as m-Y₂O₃:Eu³⁺/Ag and n-Y₂O₃:Eu³⁺/Ag. MgB₂ SMSC was prepared through an ex situ process. Results show that when the dopant content was fixed at 2.0 wt.%, the T_C of MgB₂ SMSC increased initially then decreased with the increase in the Ag content in the dopant. When the Ag content is 5%, the T_C of MgB₂ SMSC was 37.2–38.0 K, which was similar to that of pure MgB₂. Meanwhile, the T_C of MgB₂ SMSC doped with n-Y₂O₃:Eu³⁺/Ag increased initially then decreased basically with the increase in the content of n-Y₂O₃:Eu³⁺/Ag, in which the Ag content is fixed at 5%. The T_C of MgB₂ SMSC doped with 0.5 wt.% n-Y₂O₃:Eu³⁺/Ag was 37.6–38.4 K, which was 0.4 K higher than that of pure MgB₂. It is thought that the doping luminescent nanocomposite into the superconductor is a new means to improve the T_C of SMSC.