Phase Evolution Induced by Mechanical Milling in Ln2O3:TiO2 Mixtures (A = Gd and Dy)
G. García-Martínez; L.G. Martínez-González; J.I. Escalante-García; A.F. Fuentes. Phase Evolution Induced by Mechanical Milling in Ln2O3:TiO2 Mixtures (A = Gd and Dy). Powder Technology (ISSN: 0032-5910). 2005, Vol. 152, p. 72-2005.
This paper presents a study of the phase evolution induced by mechanical milling in mixtures Ln2O3:TiO2 (Ln=Gd, Dy) with two different stoichiometries, 1:1 and 1:2. Starting from oxides, pyrochlores Ln2Ti2O7 and the hexagonal h-Ln2TiO5 forms were obtained at room temperature by milling the initial mixtures in a planetary ball mill using zirconia balls and mortars. Mechanically activated chemical reactions involve titanium oxide and the monoclinic B-Ln2O3, obtained this one during the initial stages of the milling process, from the starting highly symmetric cubic form, C-Ln2O3. Differential thermal analysis of the just milled powders showed in every case, the presence of an exothermic event at temperatures close to 800 8C which is thought to be due to some order–disorder event.
This paper presents a study of the phase evolution induced by mechanical milling in mixtures Ln2O3:TiO2 (Ln=Gd, Dy) with two different stoichiometries, 1:1 and 1:2. Starting from oxides, pyrochlores Ln2Ti2O7 and the hexagonal h-Ln2TiO5 forms were obtained at room temperature by milling the initial mixtures in a planetary ball mill using zirconia balls and mortars. Mechanically activated chemical reactions involve titanium oxide and the monoclinic B-Ln2O3, obtained this one during the initial stages of the milling process, from the starting highly symmetric cubic form, C-Ln2O3. Differential thermal analysis of the just milled powders showed in every case, the presence of an exothermic event at temperatures close to 800 8C which is thought to be due to some order–disorder event.