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Electron-trapping materials have attracted a lot of attention in the field of optical data storage. However, the lack of suitable trap levels has hindered its development and application in the field of optical data storage. Herein, Lu[sub.3]Al[sub.5]O[sub.12]:Ce[sup.3+] fluorescent ceramics were developed as the optical storage medium, and high-temperature vacuum sintering induced the formation of deep traps (1.36 eV). The matrix based on the garnet-structured material ensures excellent rewritability. By analyzing the thermoluminescence and photostimulable luminescence, it is found that the transition of electrons provided by Ce[sup.3+] between the conduction band and trap levels offers the possibility for optical data storage. As evidence of its application, the optical information encoding using 254 nm light and decoding using a light stimulus and thermal stimulus were applied. These findings are expected to provide candidate material for novel optical storage technology, and further promote the development of advanced information storage technology.

Polydispersed Ag species-modified TiO[sub.2] samples with abundant oxygen vacancies were successfully prepared through the calcination of atomically precise Ag[sub.33] nanocluster-loaded TiO[sub.2] at an optimal temperature under a nitrogen atmosphere. The ligands of the Ag[sub.33] nanoclusters are removed by extracting lattice oxygen from TiO[sub.2] during the calcination, leading to the formation of CO[sub.2], SO[sub.2], and H[sub.2]O vapor. This process simultaneously induces Ag species sintering on the surface of TiO[sub.2]. The resulting nanocomposites exhibited excellent catalytic activity for the reduction of nitroarenes with NaBH[sub.4] as the reductant. This is attributed to the produced Ag species on the oxygen-deficient TiO[sub.2], which act as active centers for the catalytic process.

This research investigated the impact of Cr content on the properties of (Mo,Cr)Si[sub.2] composites. Composites with CrSi[sub.2] molar fractions ranging from 0% to 10% were fabricated using spark plasma sintering (SPS). The study undertook a systematic analysis of the surface morphology, phase composition, mechanical properties, and high-temperature oxidation resistance of the sintered samples across different compositions. Notably, the (Mo[sub.95],Cr[sub.5])Si[sub.2] composite sintered at 1400 °C exhibited enhanced properties, including a Vickers hardness of 11.6 GPa, a fracture toughness of 4.6 MPa·m[sup.1/2], and a flexural strength of 397 MPa. Upon oxidation at 1500 °C, the (Mo,Cr)Si[sub.2] composites formed a protective oxide layer comprised of SiO[sub.2] and Cr[sub.2]O[sub.3]. It was found that the generation and thickening of the protective oxide layer was promoted by the addition of moderate amounts of Cr to MoSi[sub.2].

The paper reports on effect of grain-growth inhibitors MgO, Y[sub.2]O[sub.3] and MnCO[sub.3] as well as Ca modification on the microstructure, dielectric, ferroelectric and electrocaloric (EC) properties of Ba[sub.0.82]Sr[sub.0.18]Sn[sub.0.065]Ti[sub.0.935]O[sub.3] (BSSnT). Furthermore, the effects of the sintering time and temperature on the microstructure and the electrical properties of the most promising material system Ba[sub.0.62]Ca[sub.0.20]Sr[sub.0.18]Sn[sub.0.065]Ti[sub.0.935]O[sub.3] (BCSSnT-20) are investigated. Additions of MgO (x[sub.MgO] = 1%), Y[sub.2]O[sub.3] (x[sub.Y2O3] = 0.25%) and MnCO[sub.3] (x[sub.MnCO3] = 1%) significantly decreased the mean grain size of BSSnT to 0.4 µm, 0.8 µm and 0.4 µm, respectively. Ba[sub.0.62]Ca[sub.0.20]Sr[sub.0.18]Sn[sub.0.065]Ti[sub.0.935]O[sub.3] (BCSSnT-20) gained a homogeneous fine-grained microstructure with an average grain size of 1.5 µm, leading to a maximum electrocaloric temperature change |ΔT[sub.EC]| of 0.49 K at 40 °C with a broad peak of |ΔT[sub.EC]| > 0.33 K in the temperature range from 10 °C to 75 °C under an electric field change of 5 V µm[sup.−1]. By increasing the sintering temperature of BCSSnT-20 from 1350 °C to 1425 °C, the grain size increased from 1.5 µm to 7.3 µm and the maximum electrocaloric temperature change |ΔT[sub.EC]| increased from 0.15 K at 35 °C to 0.37 K at 20 °C under an electric field change of 2 V µm[sup.−1]. Our results show that under all investigated material systems, BCSSnT-20 is the most promising candidate for future application in multilayer ceramic (MLC) components for EC cooling devices.

Mo, TiH[sub.2], Al and graphite elemental powders were used as starting materials for the activation reaction sintering process, which was employed to fabricate porous Mo[sub.2]TiAlC[sub.2]. The alteration of phase constitution, volume expansion, porosity, pore size and surface morphology of porous Mo[sub.2]TiAlC[sub.2] with sintering temperatures ranging from 700 °C to 1500 °C were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and pore size tester. Both the pore formation mechanism and activation reaction process at each temperature stage were investigated. The experimental results illustrate that the sintered discs of porous Mo[sub.2]TiAlC[sub.2] exhibit obvious volume expansion and pore structure change during the sintering process. Before 1300 °C, the volume expansion rate and porosity increase with the increment of temperature. However, with the sintering temperature above 1300 °C, the volume expansion rate and porosity decrease. At the final sintering temperature of 1500 °C, porous Mo[sub.2]TiAlC[sub.2] with a volume expansion rate of 35.74%, overall porosity of 47.1%, and uniform pore structure was synthesized. The pore-forming mechanism of porous Mo[sub.2]TiAlC[sub.2] is discussed, and the evolution of pressed pores, the removal of molding agents, the decomposition of TiH[sub.2], and the Kirkendall effect caused by different diffusion rates of elements in the diffusion reaction are all accountable for the formation of pores.

This study investigates the arc performance of Ag-Cr[sub.2]AlC composite materials. Spark plasma sintering method was employed to prepare the Ag-Cr[sub.2]AlC composite material. A self-made arc erosion device was utilized to erode the material with different times of arc. The surface of the material was categorized into three distinct areas: the eroded center area, the eroded edge area, and the heat-affected area. After one time of arc erosion, the material exhibits a relatively flat surface with a small erosion area. However, after one hundred arc erosions, the eroded area has significantly increased, accompanied by numerous splashes, protrusions, and pores. The action of the arc leads to the decomposition and oxidation of the Ag-Cr[sub.2]AlC composite material, resulting in the formation of Ag[sub.2]O, Al[sub.2]O[sub.3], and Cr[sub.2]O[sub.3] on the surface. During the process of 100 arc erosions, the breakdown current value remains relatively stable, ranging from 20 to 35 A. From the first to the 70th arc erosion, the breakdown strength consistently varies between 3 × 10[sup.6] V/m and 6 × 10[sup.6] V/m. Subsequently, there is an observed enhancement in breakdown strength, leading to the appearance of ageing. These findings establish a theoretical foundation for the application of silver-based electrical contact materials.

Rare-earth oxysulfides are a class of functional ceramic materials with excellent physico-chemical properties and rich functionality. In this study, La[sub.2]O[sub.2]S powders were prepared from La[sub.2]S[sub.3] and La[sub.2]O[sub.3] powders at 1000 °C by pressureless sintering. La[sub.2]O[sub.2]S compacts were synthesized from La[sub.2]S[sub.3] and La[sub.2]O[sub.3] powders at 800–1600 °C by spark plasma sintering. The influences of sintering temperature and time on the preparation of La[sub.2]O[sub.2]S were studied. XRD results indicated that La[sub.2]O[sub.2]S ceramics were synthesized successfully and that the lattice constants of La[sub.2]O[sub.2]S were close to the theoretical values. SEM showed that the microstructure of La[sub.2]O[sub.2]S compacts was homogeneous. The specific heat of La[sub.2]O[sub.2]S mainly came from lattice contribution, and its Debye temperature was 237 K. The UV–visible absorption spectra showed different absorption levels in the 240–300 nm range. Raman spectroscopy revealed distinct peaks at different temperatures, indicating changes in the covalence band. The relative density of La[sub.2]O[sub.2]S ceramics was 92% and lower than theoretical values. Hardness of the synthesized La[sub.2]O[sub.2]S was greater than that of Gd[sub.2]O[sub.2]S ceramics.

To know the sustainable performance of calcium-based adsorbents is one of the important aspects to realize efficient and economical carbon capture, and to systematically study the properties of natural adsorbents is conducive to their industrialization. The cyclic calcination and carbonation characteristics of a typical natural limestone were investigated using a thermal gravimetric analyzer. Two kinds of over-sintering conditions were selected to emphatically study the cyclic separation of CO[sub.2] from limestones through prolonging the calcination time and increasing the calcination temperature. The results showed that the untimely end of the chemical reaction control stage caused by excessive sintering is the direct reason for the reduction in cyclic carbonation conversion, and the changes in surface morphology of calcined products due to pore collapse and fusion are the fundamental reasons for the reduction in cyclic carbonation conversion. The excessive sintering caused by extending the calcining time or increasing the calcining temperature has great inhibition on this cycle only; the inhibition decreases rapidly in subsequent cycles. In addition, SEM and BET–BJH tests further confirm the influence of the over-sintering phenomenon. With the further increase in cycle number, the early excessive sintering has certain stimulative effects on the subsequent carbonation reaction. It is expected to provide a reference for the subsequent research and development of natural calcium-based adsorbents.

Strontium and cobalt-free LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ] is considered one of the most promising electrodes for solid-state electrochemical devices. LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ] has high electrical conductivity, a suitable thermal expansion coefficient, satisfactory tolerance to chromium poisoning, and chemical compatibility with zirconia-based electrolytes. The disadvantage of LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ] is its low oxygen-ion conductivity. In order to increase the oxygen-ion conductivity, a complex oxide based on a doped ceria is added to the LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ]. However, this leads to a decrease in the conductivity of the electrode. In this case, a two-layer electrode with a functional composite layer and a collector layer with the addition of sintering additives should be used. In this study, the effect of sintering additives (Bi[sub.0.75]Y[sub.0.25]O[sub.2–δ] and CuO) in the collector layer on the performance of LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ]-based highly active electrodes in contact with the most common solid-state membranes (Zr[sub.0.84]Sc[sub.0.16]O[sub.2–δ], Ce[sub.0.8]Sm[sub.0.2]O[sub.2–δ], La[sub.0.85]Sr[sub.0.15]Ga[sub.0.85]Mg[sub.0.15]O[sub.3–δ], La[sub.10](SiO[sub.4])[sub.6]O[sub.3–δ], and BaCe[sub.0.89]Gd[sub.0.1]Cu[sub.0.01]O[sub.3–δ]) was investigated. It was shown that LaNi[sub.0.6]Fe[sub.0.4]O[sub.3–δ] has good chemical compatibility with the abovementioned membranes. The best electrochemical activity (polarization resistance about 0.02 Ohm cm[sup.2] at 800 °C) was obtained for the electrode with 5 wt.% Bi[sub.0.75]Y[sub.0.25]O[sub.1.5] and 2 wt.% CuO in the collector layer.

Mg.sub.3Sb.sub.2 compounds were synthesized via low-temperature solid-state reaction (SSR) and ball milling (BM), respectively, followed by spark plasma sintering (SPS) process. The effects of possible sintering pressure-induced orientation in the SPS process have been investigated in terms of the microstructure and thermoelectric transport properties. The results indicate that BM technique causes more severe Mg loss than pure SSR method, leading to distinct Sb phase existing in the product after SPS consolidation process. On the contrary, a single phase of Mg.sub.3Sb.sub.2 is easily obtained with the combination of SSR and SPS techniques. Besides, these BM-SPS and SSR-SPS samples exhibit the similar microstructure as well as the same electrical and thermal transport properties parallel or perpendicular to the direction of sintering pressure. The study suggests that SSR method embodies the advantages of both the composition control and the orientation elimination in Mg.sub.3Sb.sub.2 compound as compared to BM method with the specific parameters in the current work. This investigation is quite favorable for this material fabrication and the future application of thermoelectric modules and devices.