The structure of pure amorphous Sb2O3

R.G.Orman, A.C.Hannon*, D.Holland, E.R.Barney S.A.Feller, D.E.Brown and C.E.Johnson.

We have used roller-quenching to prepare a pure sample of vitreous Sb2O3. EDX and XRF measurements show no evidence of the presence of any other elements in the sample. Previous reports of vitreous Sb2O3 in the literature have involved samples which contain a small amount of some other component in the glass. Thus, as far as we are aware, this is the first report of a pure single component Sb2O3 glass.
We have used neutron diffraction to investigate the structure of pure vitreous Sb2O3, and the predominant structural unit in the glass is an SbO3 trigonal pyramid. There are two crystal polymorphs of Sb2O3, both of which involve SbO3 pyramids; senarmontite, which is composed of isolated Sb4O6 molecules, and valentinite, which has a structure formed by infinite double chains of SbO3 units. Thus the structure of Sb2O3 has commonly been discussed in terms of these two crystal structures, considering whether it is more ‘senarmontite-like’ or more ‘valentinite-like’. However, it is more reasonable to consider whether the structure of v-Sb2O3 is best described as a molecular glass or a random network, and the neutron diffraction results are modelled on this basis.
This work was supported in part by the US National Science Foundation under grant DMR 0904615.