Structural Studies of Metastable Nanocrystalline Magnesium Titanate Ceramics

Author

Renmei Xu

Date of Award

12-2001

Degree Name

Master of Science

Department

Civil and Construction Engineering

First Advisor

Dr. Pnina Ari-Gur

Second Advisor

Dr. Massood Atashbar

Third Advisor

Dr. John B. Miller

Access Setting

Masters Thesis-Open Access

Abstract

Nanocrystalline magnesium titanate powders were produced using alkoxides of magnesium and titanium for the sol-gel method. High temperature phases which can only be formed at above 1200°C in equilibrium were formed at much lower temperature 600°C in nanometric system. Cation ordering and structural changes in qandilite (Mg₂TiO₄ ), geikielite (MgTiO₃ ) and karrooite (MgTi₂O₅ ) were studied by Rietveld refinement of neutron powder diffraction data and X-ray photoelectron spectroscopy. Single qandilite phases were obtained in a wide range of Mg:Ti ratios from 2:038:1 to 1.52:1, and appeared to be Mg_2-xTi_1+xO_4• Single geikielite phase was obtained with Mg:Ti ratio 1:1.23. Karrooite phases appeared to be Mg_1-xTi_2+xO₅• The binding energy of nanocrystalline qandilite phase became lower with lower Mg:Ti ratio. The binding energy of nanocrystalline geikielite phase was found similar to the equilibrium phase.

Recommended Citation

Xu, Renmei, "Structural Studies of Metastable Nanocrystalline Magnesium Titanate Ceramics" (2001). Masters Theses. 4779.
https://scholarworks.wmich.edu/masters_theses/4779