Preparation And Characterization Of Magnesium And Zinc Titanates

Magnesium titanate (MgTiO3) and zinc titanate (ZnTiO3) are two important microwave ceramic materials. Much attention has been focused on the synthesis of MgTiO3 because of its high Q values, low dielectric loss and dielectric constant. Meanwhile, ZnTiO3 can be mixed with Ag, Cu, etc. to prepare electrodes because of its relatively low sintering temperatures and dielectric loss. However, ZnTiO3 is easily decomposed at high temperature. Up to now, most of the studies mainly focus on improving the purity and reducing sintering temperature of MgTiO3 and ZnTiO3 ceramic powder.To improve the purity and reduce the sintering temperature of MgTiO3, investigating the phase evolution of MgTiO3 nanoparticles is very meaningful. In this work, stearic acid gel method is employed to study the phase evolution of MgTiO3 nanoparticles by Thermal gravimetric analysis, X-ray diffraction, Fourier transform infrared and Transmission electron microscopy. During the preparation of stearic acid gel, stearic acid and magnesium stearate combining with butyl titanate formed magnesium-titanium oxide network polymer, meanwhile n-butanol is generated; In the calcined process of stearic acid gel, a series of oxidation and combustion reactions occur, meanwhile apparent heat is given off; A metastable intermediate phase Mg2TiO4 is generated at 450℃and nearly disappeared at 550℃. Simultaneously, the phase of MgTiO3 appears.MgTiO3 and ZnTiO3 thin films, being special morphology materials, have been used in many scientific fields and have the potential to be integrated directly into microelectronic devices. Therefore, much attention has been focused on the synthesis of MgTiO3 and ZnTiO3. The present work is made to investigate to prepare MgTiO3 and ZnTiO3 thin film.In this work, using magnesium nitrate, zinc nitrate, butyl titanate, acetic acid, ethanol, 2-methoxyethanol and polyvinylpyrrolidone (PVP) as the starting materials, stable sol was firstly prepared, then coated on substrates (silicon), and finally annealed. In the experiments, some influence factors on the sol-gel and the thin film crystallization were investigated. The optimal conditions were chosen to synthesize uniform thin film without cracks. The obtained samples were characterized by TGA-DTA, XRD, FT-IR and AFM, respectively. The results indicate that uniform MgTiO3 and ZnTiO3 thin films can be successfully synthesized by sol-gel method.