Sökning: "transition metal clusters"

Visar resultat 1 - 5 av 33 avhandlingar innehållade orden transition metal clusters.

1. 1. Multicomponent Clusters/Nanoparticles : An Investigation of Electronic and Geometric Properties by Photoelectron Spectroscopy

   Författare :Chaofan Zhang; Olle Björneholm; Maxim Tchaplyguine; Svante Svensson; Gerd Ganteför; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Clusters; Nanoparticles; Alloy; Atmospheric chemistry; Alkali halide; Transition metals; X-ray Photoelectron spectroscopy; Polarizability; Core-shell; Sandwich structure; MAX-lab; BESSY II;

   Sammanfattning : Clusters/nanoparticles are aggregates of a “small” number of building blocks, atoms or molecules, ranging from two up to millions of atoms. Two main groups of clusters have been studied using photoelectron spectroscopy based on synchrotron radiation. LÄS MER

3. 2. Transition Metal Hydride Complexes and Hydrogenated Gallium Clusters : Synthesis and Structural Properties

   Författare :Henrik Fahlquist; Dag Noréus; Maximilian Fichtner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Metal hydrides; Solid state Synthesis; X-ray diffraction; Neutron Scattering; strukturkemi; Structural Chemistry;

   Sammanfattning : Synthesis and structural characterisation of metal hydrides in two important systems are presented. The first system presented is low valent cobalt and nickel complex hydrides with the compositions BaMg5Co2H10, RbMg5CoNiH10, SrMg2CoH7and Sr4Mg4Co3H19 featuring nickel with oxidation state of 0 and cobalt with oxidation state +I and -I. LÄS MER

4. 3. Quantum mechanical models of nanomagnetism in transition metal clusters and diluted magnetic semiconductors

   Författare :Olof Strandberg; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diluted magnetic semiconductors; Mn As; Ga; transition metal clusters; magnetic anisotropy; Nanomagnetism; quantum geometric phases; Chern numbers; effective spin Hamiltonians; dimers;

   Sammanfattning : This dissertation investigates nanomagnetism in small transition metal clusters and the diluted magnetic semiconductor (Ga,Mn)As. We derive quantum mechanical models aimed at a realistic description of the low energy physics in these systems. LÄS MER

5. 4. Reactivity of small transition-metal clusters with carbon monoxide

   Författare :Lotta Holmgren; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Co_{n< sub>}; reaction probability; Ni_{n< sub}; time-of-flight mass spectrometry; carbon monoxide; Wn_{n< sub}; Nb_{n< sub}; adsorption; laser vaporisation; supersonic beam; Cu_{n< sub};

   Sammanfattning : .... LÄS MER

7. 5. Transition metal oxofluorides comprising lone pair elements : Synthesis and Characterization

   Författare :Shichao Hu; Mats Johnsson; Jürgen Köhler; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lone pairs; oxofluorides; low-dimensional compounds; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Within the family of transition metal oxochlorides/bromides containing lone pair elements, the transition metal cations often adopt a low-dimensional arrangement such as 2D layers, 1D chains or 0D clusters. The reduced dimensionality is attributed to the presence of stereochemically active lone pairs which are positioned in the non-bonding orbital and will not participate in bond formation and instead act as structural spacers that help to separate coordination polyhedra around transition metal cations from forming three dimensional networks. LÄS MER