The oxidative dehydrogenation (ODH) of propane was investigated on vanadia dispersed on alumina containing a nominal polymolybdate monolayer (4.8 Mo/nm2). Dehydrogenation rates and selectivities on these catalysts were compared with those on vanadia domains dispersed on alumina. At a given vanadia surface density, ODH reaction rates per gram of catalyst were about 1.5–2 times greater on MoOx -c...

The first demonstration of high-Al-composition (> 70%) AlGaN high electron mobility transistors (HEMTs) is reported. High electron mobility (∼1300 cm/Vs at room temperature) was achieved in novel high-Al-composition AlGaN 2-D electron gas structures. The threshold voltages (Vth) of Al0.72Ga0.28N/AlN/GaN HEMTs were shifted from −1.0 to −0.13 V by employing different gate metal stacks, Al/Au and ...

Transformation of Al(NO3)3∙9H2O (upon heating in the range of 20-1200 °C) into blends of amorphous and crystalline boehmite (210-525 °C), amorphous alumina and crystalline γ-Al2O3 (850 °C), and crystalline α-Al2O3 (1100 °C) was analyzed using X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), infrared (IR) spectroscopy, thermogravimetry, and low-temperature nitro...

Molecular dynamics simulation was explored to investigate the change of structure of calcium aluminosilicate slags with varying Al2O3/ SiO2 ratios at a fixed CaO content. In practice the results of the study are relevant to the significant changes in slag structure caused by the changes in chemical composition during continuous casting of steels containing high amounts of dissolved aluminum. It...

This report mainly focuses on the investigation of morphological, optical, and electrical properties of Al2O3/ZnO nanolaminates regulated by varying bilayer thicknesses. The growth mechanism of nanolaminates based on atomic layer deposition and Al penetration into ZnO layer are proposed. The surface roughness of Al2O3/ZnO nanolaminates can be controlled due to the smooth effect of interposed Al...

We report a detailed investigation of the structural and chemical characteristics of thin evaporated Al2O3 tunnel barriers of variable thickness grown onto single-layer graphene sheets. Advanced electron microscopy and spectrum-imaging techniques were used to investigate the Co/Al2O3/graphene/SiO2 interfaces. Direct observation of pinhole contacts was achieved using FIB cross-sectional lamellas...

Based on density functional methods, we investigate the origin of variations in electronic structures and dielectric constants of representative alumina polymorphs. We consider the most stable -Al2O3 and three metastable phases of alumina, , , and -Al2O3. Computed energy gaps are found to be in the order of , which can be understood based on electrostatic potentials at specific lattice sites; w...