Search for dissertations about: "Rietveld refinement"

Showing result 1 - 5 of 16 swedish dissertations containing the words Rietveld refinement.

2. 1. Crystal chemistry of Fe-Ti oxides in mafic rocks and metabasites: A study aimed at refinement of geological tools and interpretations

   Author : Benyam Estifanos; Berggrundsgeologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fe-Ti oxide; hercynite; siderite; stilpnomelane; olivine corona; Swedish Caledonides; hysteresis; PIXE; synchrotron XRD; Rietveld; microprobe; red corundum; palaeomagnetism; eclogite; plagioclase clouding; dolerite; pyroxene gneiss; Geology; physical geography; Geologi; fysisk geografi;

   Abstract : This thesis consists of four subprojects: (A) ‘Clouding of plagioclase by Fe-Ti oxides’, (B) ‘Fe-Ti oxides during high-pressure metamorphism of mafic rocks’, (C) ‘Magnetic study of Fe-Ti oxides in mafic rocks and metabasites’, and (D) ‘Topotactic phase transitions in oxide minerals’. A) In southern Sweden dolerite dikes and gabbros with clouded plagioclase are common. READ MORE

4. 2. Acceptor-Doped BaZrO3 Perovskite: Synthesis, Structure and Proton Conductivity

   Author : Istaq Ahmed; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Impedance spectroscopy; Perovskite; Neutron diffraction; Rietveld refinement; BaZrO3.; Proton conductor;

   Abstract : Acceptor-doped perovskite oxides exhibit significant proton conductivity in hydrogen containing atmospheres. Therefore, they have potential for use as separator materials for various electrochemical devices including gas sensors, electrolysers and fuel cells. READ MORE

5. 3. The rational design of lithium insertion materials for battery applications

   Author : Helena Berg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; cathode materials; lithium manganese oxide; in situ neutron diffraction; Rietveld refinement; band-structure calculations; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Abstract : The transition-metal oxide spine1 LiMn2O4 is a promising cathode material for high-capacity lithium-ion batteries. Structure-property relationships pertaining to the electrochemical cycling behaviour of LiMn2O4 have been studied. READ MORE

6. 4. Proton conductivity in acceptor-doped lanthanide based pyrochlore oxides

   Author : Karinh Eurenius; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Pyrochlore; Rietveld refinement; Proton conductivity; Electrical impedance spectroscopy; Concentration Cell Electromotive Force Method.;

   Abstract : A high interest in developing new materials for SOFC applications in the temperature range of approximately 200–500 C has been growing lately. The lower activation energies for proton (H+) mobility can give higher conductivity in this temperature range. READ MORE

7. 5. Structure and Phase Stability of CaC2 Polymorphs, Li2C2 and Lithium Intercalated Graphite : A Revisit with High Pressure Experiments and Metal Hydride–Graphite Reactions

   Author : Sumit Konar; Ulrich Häussermann; Gunnar Svensson; Arnold Guloy; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; acetylide carbides; high pressure; Raman spectroscopy; powder X-ray diffraction; Rietveld refinement; Materials Chemistry; materialkemi;

   Abstract : Alkali (A) and alkaline earth (AE) metals can form carbides and intercalated graphites with carbon. The carbides mostly represent acetylides which are salt-like compounds composed of C22− dumbbell anions and metal cations. Both the acetylide carbides and intercalated graphites are technologically important. READ MORE