3,799,048 research outputs found
Spectroscopic study of high Er and Er/Yb concentration doped photosensitive silicate glasses for integrated optics application
No full textStructural study of the origin of the largest 1.5 μm Er3+ luminescence band width in multicomponent silicate glass
No full textEu2+ activated novel eulytite Na3Bi5(PO4)6: Eu3+ phosphors: Enhanced luminescence and thermal stability for photonics application
No full textFor the first time, novel eulytite-like Eu2+/Eu3+: Na3Bi5(PO4)(6) phosphor was synthesized via high temperature solid-state reaction method in reduction environment, and the structure, luminescence performances and thermal stability were investigated and discussed using various techniques. X-ray refinement diffraction and Raman spectra revealed the around 200 nm well-crystallized eulytite-type (I43d space group) phosphors were synthesized, and a diagram of crystal structure of Na3Bi5(PO4)(6) was proposed. X-ray photoelectron spectroscopy analysis confirmed the co-existence of Eu2+ and Eu3+ ions which exhibited characteristic 4f(6)5d -> S-8(7/2) transition of Eu2+ and F-7(0)-> D-5(0,1,2,3,4) transitions of Eu3+ ions. On the other hand, due to the activation of Eu2+, samples displayed good tunability on excited and emission behaviors under different excited laser. The JO parameters, emission cross-section, branching ratio and asymmetric ratio indicated that the Eu doping increased the covalency and asymmetry of host. Thermal quenching was studied and the reasons were discussed. Through the comparison of phosphors prepared in different conditions, the thermal stability & repeatability, radiative lifetime, color purity and activation energy were remarkably superior due to the Eu doping and in particularly Eu2+ activation. Finally, the energy level and CIE chromaticity diagrams were plotted to explain the mechanism of Eu2+ activation and energy transfer between Eu2+ and Eu3+ ions. The 0.5%Eu doped Na3Bi5(PO4)(6) exhibited promising tunable red-emission performance with quantum efficiency of 92%, activation energy of 0.24 eV, red color purity of 93.74% and very low non-radiative transfer ratio 44.20 s(-1) with smaller CCT (<2200 K)
Optimization of thermal assisted direct bonding of soda-lime glasses for lab-on chipapplication
No full textA new Faraday rotation measurement methodfor the study on magneto optical property of PbO-Bi2O3-B2O3 glasses for current sensor application
No full textMAGNETO-OPTICAL current transformers (MOCT) based on the Faraday Effect provide numerous ad-vantages over the conventional transformers. However the commonly used materials in MOCT are crystals that are very expensive and temperature dependence thus will cause many problems for the output signal. Cost efficient diamagnetic PbO-Bi2O3-B2O3 (PBB) glass system is fabricated in this study, for the aim of ob-taining a good candidate glass with high Verdet constant and good temperature resistance to replace crystals. A home-made optical bench was setup, calibrated and used for measuring the Verdet constant of the fabri-cated glasses. Glass with composition of 50%PbO-40%Bi2O3-10%B2O3 in mol showed high Verdet constant (0.1533 min·G–1·cm–1) and good value of the figure of merit (0.02635 min·G–1), which can be considered as the ideal candidate for MOCT applications
One-step hydrothermal synthesis ofLi2FeSiO4/C composites as lithium-ionbattery cathode materials
No full textLi2FeSiO4/C composites were one-step synthesized under hydrothermal conditions at 200 C for 72 h using glucose as carbon source. By adjusting the quantity of added glucose, we obtained varied Li2FeSiO4/C composites with different size and morphology. A series of electrochemical tests demonstrate that the Li2FeSiO4/C nanoparticles with diameters about 20 nm have higher discharge capacity, and slower capacity fading in comparison with Li2FeSiO4 and other Li2FeSiO4/C composites. Li2FeSiO4/C nanoparticles deliver a discharge capacity of 136 mAh g-1 at 0.2 C, and after 100 cycles, the discharge capacity remains 96.1%. Furthermore, Li2FeSiO4/C nanoparticles also exhibit an excellent rate capability with a capacity of about 80 mAh g-1 at 10
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