Sökning: "oxygen ordering"
Visar resultat 1 - 5 av 24 avhandlingar innehållade orden oxygen ordering.
1. YBCO nanowires to study nanoscale ordering in High-Tc Superconductors
Sammanfattning : We present the realization of YBa2Cu3O7-δ (YBCO) nanowires for both basic physics studies, which could help to elucidate the microscopic mechanisms of High critical Temperature Superconductors (HTS), and for novel applications.The first part of the thesis describes an improved nanopatterning procedure, based on e-beam lithography in combination with an amorphous carbon mask and a very gentle Ar+ ion etching. LÄS MER
2. Atom-Probe Field-Ion Microscopy of Electronic Materials
Sammanfattning : This thesis presents work in which atom-probe field-ion microscopy (APFIM) has been applied to two types of electronic materials. In the case of metal/GaAs contacts, the purpose was to characterise the microstructure of the contact interface, particularly the chemical composition variation across the interface. LÄS MER
3. Beyond average crystal structures: understanding extended and local environments in proton-conducting Sc-substituted BaTiO3 perovskites
Sammanfattning : Proton conducting ceramics are very promising for applications concerned with energy sourcing with cleaner, safer, more abundant and cheaper alternatives to fossil fuels. These materials are still in development and advances in the field depend on a better understanding of the role of defects, their identification and location in the host framework, and the assessment of their short- and long-range dynamics and kinetics. LÄS MER
4. The Electrochemistry of LiNi0.5-xMn1.5+xO4-δ in Li-ion Batteries : Structure, Side-reactions and Cross-talk
Sammanfattning : The use of Li-ion batteries in portable electronic products is today widespread and on-going research is extensively dedicated to improve their performance and energy density for use in electric vehicles. The largest contribution to the overall cell weight comes from the positive electrode material, and improvements regarding this component thereby render a high potential for the development of these types of batteries. LÄS MER
5. Density Functional Theory Applied to Materials for Spintronics
Sammanfattning : The properties of dilute magnetic semiconductors have been studied by combined ab initio, Monte Carlo, and experimental techniques. This class of materials could be very important for future spintronic devices, that offer enriched functionality by making use of both the spin and the charge of the electrons. LÄS MER