Search for dissertations about: "Barium zirconate BaZrO3"

Found 5 swedish dissertations containing the words Barium zirconate BaZrO3.

2. 1. Acceptor-doped barium zirconate: Oxidation, hydration and space-charge formation

   Author : Anders Lindman; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; BaZrO3; space charge; point defects; oxidation; GW; hydration; density functional theory; grain boundaries; interatomic potential; perovskites;

   Abstract : The current production and use of fossil fuels is not sustainable and new technologies are needed to become more independent of these fuels.The hydrogen economy, with the fuel cell as an efficient converter of chemical to electrical energy, is a desirable alternative.For this to become a reality, new materials with tailored properties are required. READ MORE

4. 2. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

   Author : Joakim Nyman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

   Abstract : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. READ MORE

5. 3. Significance of grain boundaries for transport phenomena in graphene and proton-conducting barium zirconate

   Author : Edit Ahlberg Helgee; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; graphene; density functional theory; phonons; proton conduction; grain boundaries; BaZrO3; interatomic model potentials;

   Abstract : Grain boundaries can have a significant influence on the properties of polycrystalline materials. When determining the type and extent of this influence it is frequently useful to employ computational methods such as density functional theory and molecular dynamics, which can provide models of the grain boundary structure at the atomistic level. READ MORE

6. 4. On hydrogen point defects in perovskite oxides

   Author : Erik Jedvik Granhed; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; oxyhydride; phonon; point defects; chemical expansion; polaron; BaZrO3; proton conductor; BaTiO3;

   Abstract : Oxides based on the perovskite structure exhibit a surprisingly large diversity in materials properties and are found in many different applications, several related to clean energy technologies, such as solar cells, batteries and fuel cells. Many properties in materials are the result of lattice imperfections, commonly denoted \emph{defects}, and much effort is devoted to fine tuning materials properties through controlling the defects therein. READ MORE

7. 5. Advanced BaZrO3-BaCeO3 Based Proton Conductors Used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

   Author : Junfu Bu; Pär Jönsson; Zhe Zhao; Mogens Mogensen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid oxide fuel cells SOFCs ; Intermediate temperature solid oxide fuel cells ITSOFCs ; Electrolyte; Electrochemical impedance spectroscopy EIS ; Barium zirconate BaZrO3 ; Barium cerate BaCeO3 ; Solid-state reaction SSR ; Sintering; Conventional sintering CS ; Solid-state reactive sintering SSRS ; Spark plasma sintering SPS ; Ionic conductivity; Oxygen ion conductivity; Proton conductivity; Electronic conductivity; Oxygen ion conductor; Proton conductor; Oxygen partial pressure OPP ; Composite electrolyte; Materials Science and Engineering; Teknisk materialvetenskap;

   Abstract : In this thesis, the focus is on studying BaZrO3-BaCeO3 based proton conductors due to that they represent very promising proton conductors to be used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs). Here, dense BaZr0.5Ce0.3Y0. READ MORE