Wettability and interface microstructure were studied for Nb-containing melts in the contact with ceramic oxide materials of Al2O3-SiO2 system. Ni-40.5 at.%Nb and Au-(0-20) at.%Nb alloys were investigated as prospective alloys for high temperature brazes. Ceramic samples ranged in composition from pure Al2O3 to pure SiO2. The wettability was measured by the sessile drop method. Microstructure o...

Cu nano-particles (Cu-NPs) were embedded into the SiO2 layer of a Cu/SiO2/Pt structure to examine their influence on resistive switching characteristics. The device showed a reversible resistive switching behavior, which was due to the formation and rupture of a Cu-conducting filament with an electrochemical reaction. The Cu-NPs enhanced the local electric field within the SiO2 layer, which cau...

The accurate value of thermal expansion coefficient ( ) of thin film is an important thermal property in the design of microelectronic devices and microsystem. This research presents a microbridge buckling deformation caused by the residual stresses to determine the of thermal oxide (SiO2) film. The extraction of is supported through experimental means and finite element analysis (FEM) of the b...

The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlO x ) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO2, Ni2P/SiO2, and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin de...

Kagome lattices are structures possessing fascinating magnetic and vibrational properties, but in spite of a large body of theoretical work, experimental realizations and investigations of their dynamics are scarce. Using a combination of Raman spectroscopy and density functional theory calculations, we study the vibrational properties of two-dimensional silica (2D-SiO2), which has a kagome lat...

Ab initio density functional theory and ballistic transport theory are applied to the calculation of tunneling current through ultra-thin SiO2 gate dielectrics. The Si/SiO2/Si model interface has been constructed by orienting a crystalline SiO2 (β−cristobalite) slab such that the misfit with Si (001) was minimized and no dangling bonds appear at the interface. The structure was then sandwiched ...

The influence of surface chemical treatments and of deposition of a SiO2 surface passivation layer on carrier distributions and mobility in AlxGa12xN/GaN heterostructure field-effect-transistor epitaxial layer structures is investigated. Surface chemical treatments are found to exert little influence on carrier distribution and mobility. Deposition of a SiO2 surface passivation layer is found t...

Ta2O5∕SiO2 high reflection (HR) interference coatings for λ ∼ 1 μm offer superior performance at high irradiance conditions. However, these coatings are not good candidates for high peak power conditions in comparison toHfO2∕SiO2 multilayer stacks. Here we show that the modification of the top layers design of a quarter wave Ta2O5∕SiO2 high reflector leads to 4–5 fold increase in the laser dama...

The effect of TiO2 layer applied to the conventional Fe2O3/FTO photoanode to improve the photoelectrochemical performance was assessed from the viewpoint of the microstructure and energy band structure. Regardless of the location of the TiO2 layer in the photoanodes, that is, Fe2O3/TiO2/FTO or TiO2/Fe2O3/FTO, high performance was obtained when α-Fe2O3 and H-TiNT/anatase-TiO2 phases existed in t...

Elektrokinetické vlastnosti zmesí minerálov Elektroforetický rozptyl svetla (ELS) je nová experimentálna technika umožňujúca merať spectrum elektroforetickej pohyblivosti alebo zeta (ξ) potenciálu skupiny častíc. Toto spectrum odráža distribúciu náboja a čiastočne distribúciu rozmeru týchto častíc. Avšak, okrem modálnej hodnoty napr. zeta potenciálu častíc rovnakého druhu, z ELS spektra môžeme ...