Sökning: "Cation ordering"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Cation ordering.

  1. 1. The Electrochemistry of LiNi0.5-xMn1.5+xO4-δ in Li-ion Batteries : Structure, Side-reactions and Cross-talk

    Författare :Burak Aktekin; Kristina Edström; Daniel Brandell; Wolfgang Zipprich; Fernanda Lodi Marzano; Christian Masquelier; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LNMO; High-voltage spinel; FEC; Cross-talk; Cation ordering; Oxygen deficiency; Anionic redox; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    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

  2. 2. Ion Solvation in Critical Binary Aqueous Solvents Probed by Advanced Synchrotron-Based Techniques

    Författare :Monika Witala; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; preferential ion solvation; microscopic segregation of hydrophilic ions; ion size asymmetry; critical binary liquid mixtures; 2; 6-dimethylpyridine; potassium chloride; grazing-incidence x-ray fluorescence; small-angle x-ray scattering; mesoscale ordering; x-ray beam-induced local heating;

    Sammanfattning : The Poisson-Boltzmann equation is the standard tool for studying the electrostatic interactions in electrolyte solutions, although it neglects e.g. the ion size and ion-ion correlations. Even experimentally observed specific ion effects cannot be explained in a view of this approximation. LÄS MER

  3. 3. Modelling Chemical Reactions : Theoretical Investigations of Organic Rearrangement Reactions

    Författare :Per-Erik Larsson; Sten Lunell; Nessima Salhi-Benachenhou; Olle Matsson; Osvaldo Goscinski; Ian H. Williams; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; Kvantkemi;

    Sammanfattning : Chemical reactions are ubiquitous and very important for life and many other processes taking place on earth. In both theoretical and experimental studies of reactivity a transition state is often used to rationalise the outcome of such studies. LÄS MER

  4. 4. Configurational Thermodynamics of the CeO2-Gd2O3 System : A Combined DFT, Cluster Expansion and Monte Carlo Approach to Bulk and Interfaces

    Författare :Pjotrs A. Žguns; Natalia V. Skorodumova; Andrei V. Ruban; María Verónica Ganduglia-Pirovano; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this thesis, we study the configurational thermodynamics of Ce1-xGdxO2-x/2 x ≤ 1 or CGO. We apply a combined Density Functional Theory (DFT), cluster expansion and Monte Carlo (MC) approach in which the configurational energy of CGO is described by means of the Ising-type Hamiltonian. LÄS MER

  5. 5. Defect Induced Room-Temperature Ferromagnetism in ZnO and MgO Thin FIlms and Device Development

    Författare :Mukes Kapilashrami; Lyuba Belova; E Dan Dahlberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Room-temperature ferromagnetism; intrinsic defects; un-balanced balanced magnetron sputtering; magnetic anisotropy and photoconductivity; Materials science; Teknisk materialvetenskap;

    Sammanfattning : This thesis presents the discovery of defect induced room-temperature ferromagnetism in industrially important ZnO and MgO thin films, and establishes from a systematic study, in both ZnO and MgO films, the unique phenomenon of the sequences of transitions from ferromagnetism to para-, and eventually the well known diamagnetism of the bulk as a function of film thickness. Highly oriented and high quality dense thin films of ZnO and MgO have been deposited by reactive (balanced) magnetron sputtering under different ambience conditions and deposition temperatures. LÄS MER