Sökning: "superexchange"

Visar resultat 6 - 9 av 9 avhandlingar innehållade ordet superexchange.

  1. 6. Tuning electron transfer reactions by selective excitation in porphyrin-acceptor assemblies

    Författare :Mikael Andersson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : This thesis concerns electron transfer reactions from different excited states in porphyrins, and the effect of changing the energy of the link connecting the donor and acceptor. Photoinduced electron transfer, and subsequent processes were studied using ultrashort laser pulses and nanosecond laser flash photolysis. LÄS MER

  3. 7. Conducting Polymers Containing In-Chain Metal Centres : Electropolymerisation and Charge Transport

    Författare :Johan Hjelm; Anders Hagfeldt; Emad Mukhtar; Robert Forster; A. R. Hillman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; Polymer electrochemistry; Conducting Polymers; Metal Complexes; Electropolymerization; Electron-hopping; Microelectrodes; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : Conjugated polymers that exhibit high electronic conductivities play key roles in the emerging field of molecular electronics. In particular, linking metal centres with useful electrochemical, photophysical, or catalytic properties to the backbone, or within the polymer chain itself, is a topic which has attracted a significant amount of interest lately. LÄS MER

  4. 8. Emerging Energy Possibilities

    Författare :Joanna Wiberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron transfer; dye-sensitized solar cells; D-B-A; femtosecond transient absorption;

    Sammanfattning : This Thesis presents a thorough study of the electron transfer (ET) processes, both inter-molecular - between dyes for dye-sensitized solar cells (DSSCs), and intra-molecular - in porphyrin based electron donor-bridge-electron acceptor model systems. The focus has been on charge separation and subsequent re-combination in the femtosecond-nanosecond range in both systems. LÄS MER

  5. 9. Design, Synthesis And Characterization Of Magnetic Ferrite Nanostructures : Toward Novel Permanent Magnets

    Författare :Pierfrancesco Maltoni; Roland Mathieu; Adrian Quesada; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanosystems; magnetic interactions; magnetism; ferrites; materials science; Engineering Science with specialization in Solid State Physics; Teknisk fysik med inriktning mot fasta tillståndets fysik;

    Sammanfattning : Magnetic oxide nanoparticles (NPs) may interact with each-other for example via dipolar or superexchange interactions, depending whether they are in direct contact. These interparticle interactions yield both ferro- and/or antiferromagnetic coupling and modify the energy barrier of the magnetic particle, depending upon the strength of the coupling and orientation of the particles. LÄS MER