Mn/Mg co-doped AlON ceramic with ultra-narrowband green emission combining high transparency toward a wide gamut backlight application.

Narrowband green-emission, combined with superior physicochemical stability and thermal performance, is regarded as a common pursuit in backlight display applications. However, mainstream phosphor-converted materials composed of resin or silicone resin easily encounter the dilemma of thermal decomposition and chemical corrosion for practical use. To overcome this problem, in this work, Mn/Mg co-doped AlON ceramic is successfully realized with ultra-narrowband green-emission and high transparency.

Decolorization, spectral broadening, and luminescence enhancement in Tb:YO transparent ceramics through vacuum thermal reduction.

Tb is extensively employed in magneto-optical devices and luminescent materials owing to its distinctive physical properties. However, under certain conditions, trivalent Tb readily undergoes oxidation to tetravalent Tb, significantly reducing the performance of devices containing Tb. In this Letter, we report a technique called dual-annealing (DA) post-treatment, which effectively solves Tb oxidation issues by utilizing the reducibility of the vacuum environment.

Ultrapure single-band red upconversion luminescence in Er doped sensitizer-rich ytterbium oxide transparent ceramics for solid-state lighting and temperature sensing.

Achieving single-band upconversion (UC) is a challenging but rewarding approach to attain optimal performance in diverse applications. In this paper, we successfully achieved single-band red UC luminescence in YbO: Er transparent ceramics (TCs) through the utilization of a sensitizer-rich design. The YbO host, which has a maximum host lattice occupancy by Yb sensitizers, facilitates the utilization of excitation light and enhances energy transfer to activators, resulting in improved UC luminescence.

Fabrication and Supercritical Water Corrosion Resistance of TiN/TiNC/AlO Multilayer Coating on Inconel 625 Alloy by CVD Method.

A TiN/TiNC/AlO multilayer coating was deposited on an Inconel 625 alloy by the chemical vapor deposition method as a protective barrier to improve the corrosion resistance in supercritical water. The corrosion characteristics were evaluated in a reactor at 500 °C and 25 MPa for 72 h. The surface morphology of the coated samples was relatively dense with no obvious cracks or pores observed.

Sol-Gel-Derived NiAl Coating on Nickel Alloy for Oxidation Resistance in Supercritical Water Environments.

Although nickel-based alloys are widely used in industries due to their oxidation and corrosion resistance, the pursuit of better performance in harsh environments is still a great challenge. In this work, we developed a sol-gel method to synthesize NiAl coating on a nickel alloy, assisted by a post-annealing process, and investigated the oxidation-resistant performance. The coating thickness can be controlled by designing the deposition times, which keep the pure NiAl phase stable.

First-principles study of the effect of dopants (Pd, Ni) on the formation and desorption of TO from a LiTiO (001) surface.

We investigated the effect of Pd and Ni dopants on the formation and desorption of tritiated water (TO) molecules from the LiTiO (001) surface using first-principles calculations coupled with the climbing-image nudged elastic band method. We calculated the energy barriers for TO production and desorption on the pure LiTiO surface to be 0.94 and 0.

Optimization of the Amount and Molecular Weight of Dispersing Agent PEG During the Co-Precipitation Preparation of Nano-Crystalline C-YSZ Powder.

Single-phase nano-crystalline yttria-stabilized zirconia (YSZ) powder was prepared by co-precipitation method using zirconium oxychloride (ZrOCl₂ · 8H₂O) and yttrium nitrate (Y(NO₃)₃ · 6H₂O) as raw materials and ammonium bicarbonate (NH₄HCO₃) and liquor ammonia (NH4OH) as the precipitators. In order to get the powder with favorable dispersibility, polyethylene glycol (PEG, HO(CH₂CH₂O) n H) with different molecular weights and amounts was used as a dispersant agent in the synthesis process and its effects on the YSZ powder was investigated. The scanning electron micrograph (SEM) images showed that the degree of agglomeration and the mean crystal size of YSZ powder varied with the amount and the molecular weight of PEG.

Fast crystallization of amorphous GdZrO induced by thermally activated electron-beam irradiation.

We investigate the ionization and displacement effects of an electron-beam (e-beam) on amorphous GdZrO synthesized by the co-precipitation and calcination methods. The as-received amorphous specimens were irradiated under electron beams at different energies (80 keV, 120 keV, and 2 MeV) and then characterized by X-ray diffraction and transmission electron microscopy. A metastable fluorite phase was observed in nanocrystalline GdZrO and is proposed to arise from the relatively lower surface and interface energy compared with the pyrochlore phase.

Constructing three-dimensional (3D) nanocrystalline models of Li4SiO4 for numerical modeling and simulation.

The three-dimensional (3D) nanocrystalline models of lithium silicates with the log-normal grain size distribution are constructed by constrained Voronoi tessellation. During evolution process, the algorithm is improved. We proposed a new algorithm idea by combining Genetic Algorithm (GA) with Least Square (LS) method to make up for the disadvantages of traditional genetic algorithm which may be easily trapped in local optimal solution.

Modeling multiscale evolution of numerous voids in shocked brittle material.

The influence of the evolution of numerous voids on macroscopic properties of materials is a multiscale problem that challenges computational research. A shock-wave compression model for brittle material, which can obtain both microscopic evolution and macroscopic shock properties, was developed using discrete element methods (lattice model). Using a model interaction-parameter-mapping procedure, qualitative features, as well as trends in the calculated shock-wave profiles, are shown to agree with experimental results.

Unique mechanical properties of nanostructured transparent MgAl2O4 ceramics.

Nanoindentation tests were performed on nanostructured transparent magnesium aluminate (MgAl2O4) ceramics to determine their mechanical properties. These tests were carried out on samples at different applied loads ranging from 300 to 9,000 μN. The elastic recovery for nanostructured transparent MgAl2O4 ceramics at different applied loads was derived from the force-depth data.

Yield Strength of Transparent MgAl2O4 Nano-Ceramic at High Pressure and Temperature.

We report here experimental results of yield strength and stress relaxation measurements of transparent MgAl2O4 nano-ceramics at high pressure and temperature. During compression at ambient temperature, the differential strain deduced from peak broadening increased significantly with pressure up to 2 GPa, with no clear indication of strain saturation. However, by then, warming the sample above 400°C under 4 GPa, stress relaxation was obviously observed, and all subsequent plastic deformation cycles are characterized again by peak broadening.

[Raman spectra analysis of bromine doped hydrogenated amorphous carbon (a-C : Br : H) films deposited by RF-PECVD].

Bromine doped hydrogenated amorphous carbon (a-C : Br : H) thin films were deposited on silicon wafers by rf. -plasma enhanced chemical vapor deposition (RF-PECVD) with a frequency of 13.56 MHz at room temperature using pure bromoethane as a precursor of carbon source mixed with hydrogen (H2) as a carrier gas.