Bond formation at polycarbonate | X interfaces (X = Al2_2O3_3, TiO2_2, TiAlO2_2) studied by theory and experiments

Interfacial bond formation during sputter deposition of metal oxide thin films onto polycarbonate (PC) is investigated by ab initio molecular dynamics simulations and X-ray photoelectron spectroscopy (XPS) analysis of PC | X interfaces (X = Al$_2$O$_3$, TiO$_2$, TiAlO$_2$). Generally, the predicted bond formation is consistent with the experimental data. For all three interfaces, the majority of bonds identified by XPS are (C-O)-metal bonds, whereas C-metal bonds are the minority. Compared to the PC | Al$_2$O$_3$ interface, the PC | TiO$_2$ and PC | TiAlO$_2$ interfaces exhibit a reduction in the measured interfacial bond density by ~ 75 and ~ 65%, respectively. Multiplying the predicted bond strength with the corresponding experimentally determined interfacial bond density shows that Al$_2$O$_3$ exhibits the strongest interface with PC, while TiO$_2$ and TiAlO$_2$ exhibit ~ 70 and ~ 60% weaker interfaces, respectively. This can be understood by considering the complex interplay between the metal oxide composition, the bond strength as well as the population of bonds that are formed across the interface

Aplikace číslicových filtrů pro cílové tvarování spekter signálů

Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta strojní. Katedra (352) automatizační techniky a řízen

Effect of Nb incorporation in Mo 2 BC coatings on structural and mechanical properties — Ab initio modelling and experiment

This article presents theoretical and experimental findings on the stability of orthorhombic (Mo1

Aluminum tantalum oxide thin films deposited at low temperature by pulsed direct current reactive magnetron sputtering for dielectric applications

This research aims at studying aluminum tantalum oxide thin films (AlxTayOz) deposited at low temperature for dielectric applications. These ternary oxide layers are synthesized at 180 °C by physical vapor deposition (PVD), specifically the mid-frequency pulsed direct current reactive magnetron sputtering. The deposition process uses targets made of a mixture of aluminum and tantalum in various proportions. Four target compositions are studied containing 95 at.%, 90 at.%, 80 at.%, and 70 at.% of aluminum, corresponding to 5 at.%, 10 at.%, 20 at.%, and 30 at.% of tantalum, respectively. The ternary oxide thin films of AlxTayOz are compared to aluminum oxide (AlxOz) and tantalum oxide (TayOz) layers produced in the same experimental conditions. The AlxTayOz thin films are dense, uniform, and amorphous regardless of the experimental conditions used in this study. Their chemical composition changes as a function of the target composition. The oxygen flow used during deposition also affects the chemical composition of the oxide layers and the deposition rate. The oxide thin films with tantalum are deposited at higher deposition rates and contain more oxygen. Tantalum also promotes the amorphization of the oxide layers. The highest dielectric strength is measured for the thin film containing a low amount of tantalum combined with a high amount of oxygen