Properties of Nanostructured Magnesium Metatitanate Prepared by the Sol-Gel Technique

Nanometric powders of high purity were produced using alkoxides of magnesium and titanium as precursors for the sol-gel method. Formation of geikielite from the sol-gel powders was carried out by stepwise heating of the sol-gel precipitate, and the progress of the process was followed by XRPD, TGA and DTA. Low temperature treatment of the sol-gel products removed the solvent and led to an amorphous precursor powder. At 370°C crystallization of periclase-spinel (MgO) and inception of geikielite formation took place. At 595°C a single phase of geikielite was identified. These temperatures of formation are lower than previously reported values. This product shows a lower sintering temperature and improved dielectric properties after sintering, as compared to magnesium metatitanate produced by calcination of ordinary magnesia and titania powders. Approximately a ten-fold improvement for the quality factor Q and a more uniform value of the dielectric constant ε were attained when using nanostructured powders for sintering magnesium metatitanate bodies.