Submicron Bi₄Ti₃O₁₂ particles via molten salt synthesis with alkaline sulfate

Abstract

Powder size is a major factor determining the characteristics of processing variables and end-products of ceramic materials. Conventionally, common particles sizes are employed in the micron range. It is now realized that better materials could be obtained through the use of submicron or nanoparticles, but they are available at much higher cost, leading to costly end-products. The effects of molten salt synthesis (MSS) employing two different salt systems, alkaline chloride and sulfate, were investigated. Employing a mixture of NaCl-KCl, the obtained crystals could be as large as tens of microns. The shape of crystals was thin platelet. However, MSS using Na2SO4-K2SO4 yielded a very different result. The obtained particles were very small, in the submicron range. Moreover, the synthesizing temperature for Bi4Ti3O12 was just 650oC, much lower than 850oC of MSS with NaCl-KCl. Therefore by employing MSS, it is possible to produce either Bi4Ti3O12 crystals tens of microns in size using alkaline chloride system or very fine particles in the submicron range using an alkaline sulfate system.

Keywords

• submicron particles
• nanoparticles
• molten salt synthesis
• Bi₄Ti₃O₁₂