KJ Ceramics 31

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Detailed Program

Paper Number : EL-P02

Time Frame : 12:00~13:30

Presentation Date : Friday, 28, November

Session Name : Electronic Ceramics

Session Chair 1# : -

Session Chair 2# : -

Structure Analysis of 12CaO・7Al2O3 Particles Synthesized by

Ms. Shiori MANEYAMA

Shizuoka University

[Introduction] 12CaO•7Al2O3 (C12A7) crystal structure has 12 cages in the unit cell, and two free oxygen ions are encaged in the cages. These ions can be replaced with various anions by the appropriate processing, to show various characteristics. Solution plasma processing is a method of synthesizing the material by vaporization of the liquid with a electric discharge, to be a plasma, as a reaction field. This method has advantage of rapid reaction at lower temperatures over conventional powder preparation methods because of the high density reaction field localized at the interface between liquid and gaseous phases. However, this method has been started to study in the recent years, therefore, there are many issues to be solved to apply it as a powder preparation method. In this study, C12A7 particles were synthesized from alkoxide-derived precursor solution by solution plasma processing for the low-temperature synthesis. As a result, we have identified metastable C12A7 phase and analyzed in detail the structure of the obtained metastable particles. [Experimental] Aluminum isopropoxide, calcium, ethanolamine and 2-Butanol were mixed and reacted to form precursor solution. The precursor solution was treated with solution plasma processing. As a result, we obtained precipitate on the electrode, and it was dried at 150 ¨¬C. Then the precipitates were characterized by XRD, TEM, and so on. [Results] From XRD pattern shown in figure1, the crystal structure of the obtained particles was C12A7 single phase substantially. A temperature of 1300 ¨¬C or more was necessary in the conventional solid state reaction to obtain C12A7 single phase, whereas the dried solution plasma processed powder was identified as a C12A7 single phase at room temperature. In addition, C12A7 particles exhibited same crystal symmetry with different lattice parameters. The difference in the lattice parameters may be ascribed to the smaller particle size. From the results, it was concluded that the crystalline phase of the resultant C12A7 exhibited 2 types, depending on the crystallization processes, and solution plasma processing will be a powerful tool to obtain interesting nanopowders at low-temperatures.

Acknowledgements :

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