Effects of vibration ball-milling of a powdered mixture of two gels, prepared from mixing ZrO2 and TiO2 sols, on crystallization processes during heating are studied in order to elucidate enhanced mechanochemical reactions with the aid of hydroxyl groups. TiO2 (anatase) and ZrO2 (tetragonal) crystallized at 698 K and 712 K, respectively, when heatingnon-milled gel mixture at 10 K min-1 in air. Few reactions between the two phases were detected below 1023 K. After vibro-milling a powdered gel mixture at room temperature for 3 to 30 h, ZrTiO4 (orthorhombic) crystallized directly from non-crystalline precursors on heating to 1023 K. The fraction of crystallized ZrTiO4, determined by Raman spectroscopy, increased linearly with increasing the index of micro-homogeneity for non-heated gels. We suggest that short-range ordering of ZrTiO4 rather than crystallization of individual oxides occurs through the non-thermal atomic movement between different metallic species under mechanical stress.
|ジャーナル||Materials Research Society Symposium - Proceedings|
|出版ステータス||Published - 1994|
|イベント||Proceedings of the 1994 MRS Spring Meeting - San Francisco, CA, USA|
継続期間: 1994 4月 4 → 1994 4月 8
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