CLASS FORMATION AND STRUCTURE IN THE SYSTEM CU2O-P2O5-MOO3

Glass formation was observed in a wide region in the system Cu2O-P2O5- MoO3, except for compositions near the area of the binary Cu2O-MoO3 co mposition. The transformation temperature was mainly controlled by the packing density of the glass network. The structure of the glasses, w hich depends strongly on composition, was studied by infrared spectros copy. The presence of various phosphate and molybdate structural units , from discrete monomeric to those with three-dimensional networks, wa s observed. P(2)O5(-) and Cu2O-rich glasses are composed mainly of (PO 3-)(n) chains, Cu2O- andMoO(3)-rich glasses are composed mainly of dis crete MoO42-, Mo2O72- and PO43- anions and, finally, the structure P2O 5- and MoO3-rich glasses is predominantly built up by a three-dimensio nal network of the MoO2(PO3)(2) type.