Transparent ceramics have various potential applications such as infrared (IR) windows/domes, lamp envelopes, opto-electric components/devices, composite armors, and screens for smartphones and they can be used as host materials for solid-state lasers. Transparent ceramics were initially developed to replace single crystals because of their simple processing route, variability in composition, high yield productivity, and shape control, among other factors. Optical transparency is one of the most important properties of transparent ceramics. In order to achieve transparency, ceramics must have highly symmetric crystal structures; therefore, the majority of the transparent ceramics have cubic structures, while tetragonal and hexagonal structures have also been reported in the open literature. Moreover, the optical transparency of ceramics is determined by their purity and density; the production of high-purity ceramics requires high-purity starting materials, and the production of high-density ceramics requires sophisticated sintering techniques and optimized sintering aids. Furthermore, specific mechanical properties are required for some applications, such as window materials and composite armor. This review aims to summarize recent progress in the fabrication and application of various transparent ceramics.

Materials development and potential applications of transparent ceramics: A review

This paper reviews work on flashlamp-pumped solid state lasers and discusses diode-pumped solid state lasers, the Mercury laser in particular. It also discusses ICF lasers beyond Mercury.

/pdf/diode-pumped-solid-state-laser-drivers-for-inertial-fusion-2mdsvqa1zu.pdf

Diode-pumped solid-state laser drivers for inertial fusion energy

Magnesium oxide (MgO) nanoparticles are one of the highly significant compounds in construction. The novelty concentrated on using sol–gel technique coupled with ultrasonication for synthesis of MgO nanoparticles to prevent the agglomeration and its effect on the size was investigated. The synthesized samples were characterized by TGA, DSC, XRD, FTIR, SEM, EDX mapping, DLS, and HRTEM. Antimicrobial and antibiofilm activities of MgO nanoparticles were investigated against multidrug-resistant microbes causing-urinary tract infection (UTI). TGA, XRD, and FTIR characterization were used to identify the calcination temperature, characterization peaks, and functional groups of MgO nanoparticles, respectively. DLS technique confirmed the particle size distribution which found to be 21.04 nm. HRTEM and SEM/EDX mapping showed that MgO nanoparticles are pure, spherical and the average particle size is 19.2 nm. MgO nanoparticles showed a promising antimicrobial effect against all UTI-causing pathogens. It showed a prominent antimicrobial capability against Staphylococcus aureus, Escherichia coli and Candida albicans by 19.3 mm, 16.1 mm and 15.2 mm ZOI, respectively. Additionally, they showed improved biofilm inhibition as 95.65%, 84.23%, and 76.85% against C. albicans, E. coli and S. aureus, respectively. Therefore, due to these outstanding properties, this study could give insights for solving serious industrial, pharmaceutical and medical challenges throughout the utilization of new nanoparticle-based approach.

Response Surface Methodology Optimization of Mono-dispersed MgO Nanoparticles Fabricated by Ultrasonic-Assisted Sol–Gel Method for Outstanding Antimicrobial and Antibiofilm Activities

Efficient and green production of biodiesel catalyzed by recyclable biomass-derived magnetic acids

Y2O3:Yb3+ 5 at% ceramics have been synthesized by the reactive sintering method using different commercial yttria powders (Alfa-Micro, Alfa-Nano, and ITO-V) as raw materials. It has been shown that all Y2O3 starting powders consist from agglomerates up to 5–7 µm in size which are formed from 25–60 nm primary particles. High-energy ball milling allows to significantly decreasing the median particle size D50 below 500 nm regardless of the commercial powders used. Sintering experiments indicate that powder mixtures fabricated from Alfa-Nano yttria powders have the highest sintering activity, while (Y0.86La0.09Yb0.05)2O3 ceramics sintered at 1750 °C for 10 h are characterized by the highest transmittance of about 45%. Y2O3:Yb3+ ceramics have been obtained by the reactive sintering at 1750–1825°C using Alfa-Nano Y2O3 powders and La2O3+ZrO2 as a complex sintering aid. The effects of the sintering temperature on densification processes, microstructure, and optical properties of Y2O3:Yb3+ 5 at% ceramics have been studied. It has been shown that Zr4+ ions decrease the grain growth of Y2O3:Yb3+ ceramics for sintering temperatures 1750–1775 °C. Further increasing the sintering temperature was accompanied by a sharp increase of the average grain size of ceramics referred to changes of structure and chemical composition of grain boundaries, as well as their mobility. It has been determined that the optimal sintering temperature to produce high-dense yttria ceramics with transmittance of 79%–83% and average grain size of 8 µm is 1800 °C. Finally, laser emission at ∼1030.7 nm with a slope efficiency of 10% was obtained with the most transparent Y2O3:Yb3+ 5 at% ceramics sintered.

/pdf/effect-of-starting-materials-and-sintering-temperature-on-516x7pa0nx.pdf

Effect of starting materials and sintering temperature on microstructure and optical properties of Y 2 O 3 :Yb 3+ 5 at% transparent ceramics

Investigation of optical, mechanical, and thermal properties of ZrO2-doped Y2O3 transparent ceramics fabricated by HIP

Fabrication of transparent yttria ceramics by alcoholic slip-casting

Despite being the most common sintering additive of transparent Y 2 O 3 ceramics, La 2 O 3 still suffers from weight changes when used in manufacturing processes due to its absorption of moisture and carbon dioxide. In the present work, two stable precursors, La(OH) 3 and La 2 O 2 CO 3 , were proposed for use as sintering additives for transparent Y 2 O 3 ceramics; La 2 O 3 powder was used for comparison. A series of experiments were conducted to investigate the influences of La 2 O 3 , La(OH) 3 and La 2 O 2 CO 3 on the optical properties of Y 2 O 3 ceramics by comparing the properties of mixed powders, green bodies and their sintering behaviors. Samples using La(OH) 3 or La 2 O 2 CO 3 as sintering additives exhibited more favorable optical properties at similar sintering temperatures compared to those using La 2 O 3 . Transmittances close to the theoretical value at 4 μm were achieved for samples doped with La(OH) 3 or La 2 O 2 CO 3 sintered at 1800 °C.

Fabrication of transparent La-doped Y2O3 ceramics using different La2O3 precursors

Influence of moisture absorption on the synthesis and properties of Y2O3-MgO nanocomposites

ZrO2 is considered an efficient sintering additive for transparent Y2O3 ceramics. However, the doping of tetravalent Zr4+ ions leads to a dark brown color of the ceramic after vacuum sintering. In this study, the optical properties of vacuum-sintered and air-annealed ceramics were characterized using transmittance spectra and a Commission International de l’Eclairage (CIE) diagram. The corresponding defects are investigated by electron paramagnetic resonance (EPR) spectra. The band gap of the vacuum-sintered samples is 2.72 eV, which is much smaller than that of the annealed sample. The results reveal that the VO+ (F+ center) and Zr3+ defects form transition energy levels near the top of the valence band and at the bottom of the conduction band, respectively. The color-related absorption is mainly attributed to the electronic transfer from the Zr3+ level to the conduction band and from the F+ center to the Zr3+ level.

Xiaokai Li

Papers

Investigation of optical, mechanical, and thermal properties of ZrO2-doped Y2O3 transparent ceramics fabricated by HIP

Fabrication of transparent yttria ceramics by alcoholic slip-casting

Fabrication of transparent La-doped Y2O3 ceramics using different La2O3 precursors

Influence of moisture absorption on the synthesis and properties of Y2O3-MgO nanocomposites

Optical absorption and mechanism of vacuum-sintered ZrO2-doped Y2O3 ceramics