Search Results

You are looking at 1 - 3 of 3 items for :

  • Refine by Access: All Content x
Clear All

Abstract  

Bi-peroxotitanate was synthesized by a peroxo method and after thermal decomposition Bi2Ti2O7 was obtained. DTA, TG and DSC curves of Bi2[Ti2(O2)4(OH)6]5H2O were recorded and used to determine isothermal conditions suitable for obtaining the intermediate samples corresponding to the phases observed during the thermal decomposition. The samples were identified by quantitative analysis, IR spectroscopy and X-ray analysis. The experimental results were used to propose a mechanism of thermal decomposition of the investigated compound to a nanosized Bi2Ti2O7. The optimum conditions were also determined for obtaining Bi2Ti2O7, which is applicable for piezosensors.

Restricted access

Abstract  

High-temperature X-ray diffraction, absorption–reflection infrared spectrometry and thermal analysis coupled on-line to mass spectrometry, were applied to citratoperoxo precursor gels and films of (Bi,Nd)4Ti3O12 (BNdT). A slow heating rate resulted in secondary phases (Bi2Ti2O7 and Bi2O3) while a high rate yielded phase pure layered perovskite BNdT. Comparison of the evolved gas profiles from the bulk gel and thin film, showed complete decomposition of the film at lower temperature than expected from thermogravimetric and evolved gas analysis of the bulk gel. Thermal methods adapted to thin films, therefore are crucial for understanding and controlling the oxide formation in the film.

Restricted access

Abstract  

Preliminary examinations regarding formation of bismuth titanates in a part of Bi2O3—TiO2 system rich with TiO2 have been carried out. Bismuth titanates have been synthesized from mixtures of Bi2O3 and TiO2 (anatase) by the conventional solid-state method at the temperatures ranged from 1273 to 1473 K. Differential thermal analysis (DTA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been used to study the formation of bismuth titanates. The following compounds have been achieved: Bi4Ti3O12, Bi2Ti2O7 and Bi2Ti4O11. Existence of controversial bismuth titanate of formula Bi2Ti3O9 in the Bi2O3—TiO2 system has not been confirmed.

Restricted access