Synthesis and characterization of BaTiO3/-Fe2O3 core/shell structure

Multiferroic materials attracted a lot of attention in recent years because of their significant scientific interest and technological applications. The multiferroic core/shell powders have a better connectivity between the phases, resulting in superior dielectric and magneto electric properties. In this study, the influence of preparation condition on structure and properties of BaTiO3/-Fe2O3 core/shell composite materials was examined. The five samples were obtained by varying synthesis conditions, such as synthesized method (co-precipitation and sonochemical method) and pH values of solution. XRD and Raman spectroscopy analyses were performed in order to determine phase composition and structural changes within samples. Morphology modifications were examined by SEM and EDS analyses. Finally, effect of structural and microstructural changes on magnetic and electrical properties was detected and explained

New digital method of microstructural characterization of sintered materials

Since a lot of physical properties of novel materials are determined by their microstructure it is very important to predict and control materials microstructure and its evolution, both in technological process of material fabrication and under different regimes of operation in products. In all these cases microstructural characterization of materials play a very important role. Having this in mind, in this article new digital method has been performed. Microstructural analysis was performed on tribophysically activated BaTiO3 and liquid phase sintered BaTiO3

Dielectric properties of barium-titanate sintered from tribophysically activated powders

It has been well known that the tribophysical (mechanical) activation could be used as a method for modification of physicochemical properties of dispersed systems such as polycrystalline mixture of oxides. In this study, we consider the properties of BaTiO3 obtained from tribophysically activated initial powders. The mixture of 50 mol% BaCO3 and 50 mol% TiO2 powders was tribophysically activated in high energy vibromill curing 0, 3, 30, 90 and 180 min, calcinated at 800 degrees C for Ih and reaction sintered at 1100, 1200 and 1300 degrees C for 2 h. The surface specific areas, densities (green and sintered), phase compositions and dielectric properties were evaluated

Screen printed barium titanate thick films prepared from mechanically activated powders

Barium titanate thick films were prepared from mechanically activated powders based on BaCO3 and TiO2. The thick films were screen-printed on alumina substrates electroded with Ag/Pd. The BT films were sintered at 850 degreesC for 1 hour. The thickness was 30-75 mum depending of number of layers. The microstructure of thick films and the compatibility between BT layers and substrate was investigated by SEM. The dielectric properties were measured and the results were reported

Kinetics of thermally activated processes in cordierite-based ceramics

Thermally activated processes in cordierite-based ceramics were investigated to determine the effect of the mechanical activation and the addition of TeO2 on kinetic and thermodynamic parameters of these processes. Using a combination of dilatometry and DTA measurements in the 100–1400 °C temperature range, it was established that both the mechanical activation and the addition of TeO2 have a significant effect on processes in cordierite-based ceramics. A combination of 5 mass% addition of TeO2 and mechanical activation for 40 min reduced the sintering temperature of cordierite ceramics to around 1100 °C. In addition, the analysis of DTA measurements of mechanically activated samples indicates that the mechanical activation leads to intensification of the cordierite formation through an increase in concentration of surface defects and an increase in grain contact surface in the initial powder.Peer-reviewed manuscript: [http://aspace.agrif.bg.ac.rs/handle/123456789/5733