Solid-Phase Synthesis of Multi-Component Ceramics (Mg,Ca,Ba,Sr,Pb,Al,Ti,Nb)O3 with Perovskite Structure
Abstract
This paper presents the results of the preparation and study of multi-component ceramics with the perovskite structure, the composition of which reflects the formula (Mg,Ca,Ba,Sr,Pb,Al, Ti,Nb)O3. Samples were obtained by solid-phase synthesis. The initial components of the charge were powders of BaCO3, Nb2O5, Al2O3, SrCO3, CaCO3, MgO, PbO, TiO2. The powder mixture was ground by a ball mill to obtain a homogeneous mixture. The finished powder formulations were compacted into cylinder shapes. The pressing process was carried out with the use of a metal mold and a hydraulic press. Sintering was carried out on a platinum substrate in a tubular furnace with silicon carbide heaters at 1350 °C for 5 hours.
After sintering the samples were ground into powder to further study their structure and chemical composition. The chemical composition of the obtained samples was studied by a JEOL JSM 7001F scanning microscope equipped with an energy-dispersive X-ray fluorescence analyzer INCA Х-max 80 (Oxford Instruments). The structure was studied on a Rigaku Ultima IV powder diffractometer by X-ray phase analysis. The results of electron microscopic investigation showed that the studied samples contained a large number of cubic crystals, which composition had the perovskite structure with the formula (Mg,Ca,Ba,Sr,Pb)(Al,Ti,Nb)O3. Besides, the composition of the samples contained crystals of different composition and shape.
The X-ray phase study of the samples confirms this conclusion. The studied samples contain a large amount of material with the perovskite structure (the pure samples from the database closest to this phase are CaTiO3, SrTiO3). Along with this, in the composition of the studied samples niobates and niobate-titanates of alkaline earth metals are present in significant quantities.
Further studies in this direction should make it possible to obtain monophasic samples of these kinds of substances suitable for studying their electromagnetic characteristics.