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Ball milling of TiO2 and ZrO2

High-energy ball milling of TiO2 and ZrO2 powders induce changes of crystal structure and decrease of particle sizes. Structural changes for different milling condition and possible solid-state reaction in mixture of these oxides were investigated by Raman spectroscopy. Changes of particle dimension were monitored by transmission electron microscopy. The results were compared with our previous experiments performed in different milling assembly. The different milling time of TiO2 induced sequence of phase transitions, from anatase through high-pressure TiO2 II phase to rutil. The kinetics of phase transition depended on powder-to-ball weight ratio. Monoclinic ZrO2 was partially transformed to tetragonal phase during milling. The milling of mixture of oxides did not complete the solid-state reaction, so the subsequent heating was necessary. In both materials prolonged milling decreased the particle to nanometric sizes. The milling induced phase transition for which otherwise high temperature or high pressure were necessary, and it was shown to be a simple method for preparation of nanoparticles.

ball milling ; Raman spectroscopy ; electron microscopy ; TiO2 ; ZrO2 ; phase transition ; nano particles

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