Nanostructured ceramics and their composites possess improved properties such as tensile strength, fatigue strength, hardness, and wear resistance. Freestanding, near-net shape, nanostructured Al2O3 components can be synthesized via plasma-spray forming. In this study, plasma-spray parameters were optimized and an innovative substrate cooling technique was developed to retain nanosize Al2O3 in ...

The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over alumina supported nickel catalysts prepared by impregnation reduction method and mechanical mixing method. The catalysts were characterized by XRD and FESEM. The results show that the nickel particle diameter of alumina supported nickel prepared by impregnation reduction method (denoted as Ni/Al2O3) is slightly ...

This work presents vertical flash memory devices with protein-assembled PbSe nanocrystals as a floating gate and Al2O3 as a control oxide. The advantage of a vertical structure is that it improves cell density. Protein assembly improves uniformity of nanocrystals, which reduces threshold voltage variation among devices. The introduction of Al2O3 as a control oxide provided lower voltage/faster ...

The characterization of mixed oxides of TiO2/SiO2 and TiO2/Al2O3 prepared by sol-gel methods is described. Application of the TiO2/Al2O3 material for the photocatalytic decomposition of salicylic acid gave improved activity relative to TiO2-only materials. The photocatalytic activity of TiO2/SiO2, TiO2/Al2O3, and TiO2 toward the photocatalytic decomposition of phenol demonstrated the enhancemen...

Corundum, a-Al2O3, is the thermodynamically stable phase of coarsely crystalline aluminum oxide, but syntheses of nanocrystalline Al2O3 usually result in g-Al2O3. Adsorption microcalorimetry, thermogravimetric analyses, and Brunauer-Emmett-Teller adsorption experiments, coupled with recently reported high-temperature solution calorimetry data, prove that g-Al2O3 has a lower surface energy than ...

In this study, the physical and electrical characteristics of Al2O3/La2O3/Al2O3/Si stack structures affected by the thickness of an Al2O3 barrier layer between Si substrate and La2O3 layer are investigated after a rapid thermal annealing (RTA) treatment. Time of flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) tests indicate that an Al2O3 barrier laye...

Al2O3 is commonly used as host material for Er-doped integrated optical amplifiers. In this paper, a Graeco-Latin square is used in DC reactive magnetron sputtering deposition experiment in order to get low optical losses Al2O3 layer. By reasonable selection and careful arrangement of experimental parameters, an optimal combination of deposition parameters is obtained via statistic analysis wit...

High-temperature surface-enhanced Raman scattering (SERS) sensing is significant for practical detections, and pinhole-containing (PC) metal@oxide structures possessing both enhanced thermal stability and superior SERS sensitivity are served as promising SERS sensors at extreme sensing conditions. Through tuning the Al2O3 precursors' exposure time during atomic layer deposition (ALD), Al2O3 she...

The addition of small amounts (2-10 wt %) of SiO2 to γ-Al2O3 increases the temperature of heat treatment necessary for transformation to R-Al2O3 by ∼100 K. We have studied this system using high-temperature solution calorimetry in molten 2PbO‚B2O3 at 1043 K. Our results indicate that the spinel-type Al2O3-SiO2 solid solutions with 2-10 wt % SiO2 are always energetically metastable by 30-35 kJ‚m...

Cu–Zn/γ–Al2O3 catalysts were prepared by the impregnation method. Catalytic activity was evaluated for N2O decomposition in a fixed bed reactor. The fresh and used catalysts were characterized by several techniques such as BET surface area, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The Cu–Zn/γ–Al2O3 catalysts exhibit high activity and stability for N2O decomposition in mi...