Barium strontium titanate, often abbreviated as Ba1-xSrxTiO3 to clearly define its composition, is a ferroelectric material with a perovskite structure (ABO3 structure). It is a material of interest as it combines beneficial properties such as a high dielectric constant, low dissipation factor and a compositional-dependent Curie temperature (Tc). It also has good thermal and mechanical stabilities.
Barium strontium titanate can be prepared by either solid state or wet chemical techniques including co-precipitation, sol-gel and hydrothermal methods. Both routes have their own relative advantages and disadvantages.
In this work by Teoh Wah Tzu, Zainal Arifin Ahmad and Ahmad Fauzi Mohd Noor from Universiti Sains Malaysia, the researchers used a mixed oxide solid state technique in conjunction with mechanical activation.
This technique was found to be able to lower the required calcination temperature when compared to other solid state production techniques such as ball milling. It also has the advantage in that it produces more homogenous materials.
Samples were then prepared from the calcined powers and sintered at various temperatures to determine the optimal processing temperature. This was determined by examining microstructure and correlating it against dielectric strength.
Results indicated that the mechanical activation route has advantages over conventional ball milling as the required calcination temperature is lower, reducing processing costs. Furthermore, the materials produced have superior properties compared to those produced using conventional ball milling, which may pave the way for this technique to be used in semiconductor manufacture.
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