Date of Award
Master of Science
Civil and Construction Engineering
Dr. Pnina Ari-Gur
Dr. James W. Richardson Jr.
Dr. John B. Miller
Masters Thesis-Open Access
Magnesium titanium oxide powders were synthesized by the sol-gel method using alkoxides of magnesium and titanium with different ratios. Matastable phases of qandilite, Mg2TiO4, were found with Mg:Ti ratios down to 1.52:1 in lower temperature 600 °C than in the equilibrium condition which is above 1200 °C. Powder samples were examined by neutron powder diffraction and X-ray photoelectron spectroscopy (XPS) for analysis of structure and oxidation states. Also, samples were tested for the Mg:Ti ratios by induced coupled plasma atomic emission spectrometry. The structure refinements of the samples were done by General Structure Analysis System (GSAS) using the Rietveld refinement method. Particle sizes were calculated from structure refinement. For the X-ray photoelectron spectroscopy analysis the commercial geikielite, MgTiO3, and qandilite, Mg2TiO4 which was annealed at 1180 °c were used as references when were compared with nanostructured samples. The XPS results showed that Ti cations had lower oxidation states in the metastable samples with Mg:Ti ratios 1.52:1 and 2:1 than in the sample that was created under the stable condition in order to keep charge balance for the samples.
Ma, Liang-Chieh, "Metastable Phases of Mgo-TiO2 Solid Solutions" (2002). Master's Theses. 4334.