Sökning: "oxygen vacancy"

Visar resultat 6 - 10 av 35 avhandlingar innehållade orden oxygen vacancy.

1. 6. Optical properties of point defects in insulators and of transition metal dichalcogenides

   Författare :Christopher Linderälv; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; luminescence quenching; charge transition levels; excitons; transition metal dichalcogenides; monolayer alloys; solid state lighting; color centers; oxygen vacancies; moiré structures; wide band gap oxides;

   Sammanfattning : There is a need for new or modified materials, both to improve current devices and to create novel functionalities. Engineering materials to target specific functionalities requires a better understanding of how microscopic processes impact materials properties. LÄS MER

3. 7. From the Electronic Structure of Point Defects to Functional Properties of Metals and Ceramics

   Författare :David Andersson; Börje Johansson; Pavel Korzhavyi; Benjamin Burton; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; first principles; ab initio; density functional theory; Calphad; point defects; diffusion; solid electrolytes; oxygen storage materials; Material physics with surface physics; Materialfysik med ytfysik;

   Sammanfattning : Point defects are an inherent part of crystalline materials and they influence important physical and chemical properties, such as diffusion, hardness, catalytic activity and phase stability. Increased understanding of point defects enables us to tailor the defect-related properties to the application at hand. LÄS MER

4. 8. Dynamics in Ceria and Related Materials from Molecular Dynamics and Lattice Dynamics

   Författare :Anders Gotte; Kersti Hermansson; Micael Baudin; Anatoly Belonoshko; Uppsala universitet; []
   Nyckelord :Inorganic chemistry; molecular dynamics; diffusion; surface dynamics; ionic surfaces; Oorganisk kemi;

   Sammanfattning : In discussions of heterogeneous catalysis and other surface-related phenomena, the dynamical properties of the catalytic material are often neglected, even at elevated temperatures. An example is the three-way catalyst (TWC), used for treatment of exhaust gases from combustion engines operating at several hundred degrees Celsius. LÄS MER

5. 9. Structure and properties of FeAl as influenced by processing

   Författare :HELENA SKOGLUND; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EDS; mechanical alloying; FeAl; Al2O3 precipitates; boron-doping; powder processing; diffusion; vacancies; mechanical properties; hardening mechanisms;

   Sammanfattning : Iron aluminides are candidate materials for a sustainable society since they are composed of abundant metals and have excellent corrosion properties in combination with high specific strength. However, there are some drawbacks that limit the practical use, e.g. low RT ductility and a drop in strength at high temperature. LÄS MER

7. 10. Atomic short-range order, optical and electronic properties of amorphous transition metal oxides : An experimental and theoretical study of amorphous titanium aTiO2 and tungsten aWO3 solid thin-film oxides

   Författare :Carlos A Triana; Tomas Edvinsson; Petter Persson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray-Absorption; Reverse Monte Carlo; Molecular dynamics; Electronic structure;

   Sammanfattning : Amorphous transition metal oxides [aTMOs], have emerged as innovative functional materials for wide-ranging electronic, optical and energy-related applications. However, no systematic and broadly applicable method exists to assess their atomic-scale correlations, and since the optical and electronic processes are local structure-dependent, still there are not well-stablished mechanisms that suitably explain the physical properties of aTMOs. LÄS MER