Reactivity and structural properties of a mechanochemically treated Ag2O-V2O5 system in relation to AgVO3 polymorphs

摘要

Formation and chemical properties of amorphous AgVO3, which was prepared by mechanochemical treatment of an Ag2O-V2O5 mixture, and crystaffine AgVO3 were studied in relation to AgVO3 polymorphs. A ball-milled sample of the mixture was assigned as a highly deformed beta-AgVO3 rather than the low density phase alpha-AgVO3. Crystalline alpha-AgVO3 and beta-AgVO3 were converted into deformed beta-AgVO3 by ball milling, which produced a clear change. delta-AgVO3 is resistant to mechanical treatment and its structure was not markedly affected. The dissolved chemical species from the ball-milled sample precipitates to form alpha-AgVO3 without a seeding crystal, but other polymorphs deposit if they are present; i.e., beta-AgVO3 and delta-AgNO3 grow on the seeding crystal. (C) 2002 Elsevier Science (USA). [References: 12]