extended metastable solid solutions by grinding has been Solid solution formation induced by dry ball-milling under well demonstrated in metallic systems ( ), but has just an argon atmosphere has been investigated in binary mixtures begun to be investigated in oxide systems.
from the TiO 2 -SnO 2 -V 2 O 5 system mainly by X-ray diffraction
Recent articles report polymorphic transformations inand differential scanning calorimetry. Grinding experiments duced by milling upon single oxides (5, 14-18) or binary followed by heat treatments result in substantial solid solubilioxide systems such as ZrO 2 -M x O y with M ϭ Y, Ca, Fe, ties in all three binaries. Under our experimental conditions, Mg, . . . . the solubility after grinding depends solely on the nature of In this paper the TiO 2 -SnO 2 , TiO 2 -V 2 O 5 , and SnO 2grinding media particularly in V 2 O 5 based systems, when reduc-V 2 O 5 systems have been investigated mainly because their tion reactions take place between grinding tools and oxide miscibilities are not very well known and the previously particles. The results demonstrate that the interaction between reported influence of grinding on the single oxides TiO 2 TiO 2 or SnO 2 and V 2 O 5 follows from the fact that SnO 2 and and SnO 2 should moreover allow a better understanding TiO 2 are first slightly reduced during milling and subsequently reoxidized by V 2 O 5 . These interactions promote solid solution of mechanisms (6). Moreover, V 2 O 5 -based binary oxide formation and the development of a reduced disordered vanasystems are of great interest in catalysis for selective oxidadium oxide layer at the surface of SnO 2 grains. The final state tion of hydrocarbons or ammonidation processes (21-23) of powders, where the interface density between both oxides is and maximum contact between both oxides leads to maxivery high, could be of interest in catalysis.