Study of effect of chromium on titanium dioxide phase transformation
Résumé
MTiX samples with different atomic chromium percentages were synthesized by sol gel method and calcined at 400 degrees C under air. The effects of Cr and temperature on titanium dioxide phase transition were studied. In situ measurement showed the presence of anatase phase for all samples at temperature <500 degrees C. Without Cr content, the anatase rutile transition takes place at 600 degrees C and the rutile fraction increases with increase of temperature. In the presence of Cr content, rutile phase appeared at 700 degrees C. Cr2O3 phase was shown only in the case of CrTi20 content at 800 degrees C which indicates that the segregation remains modest. We have also studied the anatase rutile transition kinetics by using in situ X-ray measurements. It was found that the anatase phase stability increases as the chromium content increases. Results confirm that the transformation of anatase rutile is of first order.