Show simple item record Martin Charles en_US Chris J. en_US J. K. Richard en_US 2010-01-15T11:30:07Z 2010-01-15T11:30:07Z 2008-07 en_US
dc.identifier en_US
dc.identifier.citation Wilding , M C , Benmore , C J & Weber , J K R 2008 , ' In situ diffraction studies of magnesium silicate liquids ' Journal of Materials Science , vol 43 , no. 14 , pp. 4707-4713 . , 10.1007/s10853-007-2356-5 en_US
dc.identifier.other PURE: 143426 en_US
dc.identifier.other dspace: 2160/3987 en_US
dc.description.abstract Primitive MgO–SiO2 liquids dominate the early history of the Earth and Terrestrial planets. The structures of these liquids and structure-dependent properties, such as viscosity and diffusion, are considered important in the evolution of these planets, however, MgO–SiO2 liquids are refractory and do not form glasses easily and it is difficult to measure the structure of these liquids. Container-less synthesis techniques have been used to produce glasses that range in composition from 50 to 33% SiO2, corresponding to the compositions of two important mantle minerals: enstatite and forsterite. The structure of these glasses has been determined using combined neutron and high-energy diffraction and show changes in the short-range order as a function of composition. These changes include a jump in Mg–O coordination number at the limit to the formation of the silicate network in forsterite composition glass. These results imply a similar change in the structure of the liquid. Accordingly, the structures of forsterite and enstatite liquids have been determined using high-energy X-rays and a specialized sample environment, a containerless levitator. The main qualitative structural differences between MgSiO3 and Mg2SiO4 glasses are also observed in the melt. Liquid MgSiO3 is interpreted as forming a relatively ‘strong’ network of SiO4 tetrahedra, whereas the Mg2SiO4 liquid is “fragile” and dominated MgO n (n = 4, 5, 6) polyhedra and highly mobile oxygen ions. The results differ significantly from previously reported X-ray diffraction data for liquid MgSiO3. en_US
dc.format.extent 7 en_US
dc.relation.ispartof Journal of Materials Science en_US
dc.subject HIGH-PRESSURE en_US
dc.subject VITREOUS SILICA en_US
dc.subject X-RAY-DIFFRACTION en_US
dc.subject PHASE en_US
dc.subject AMORPHOUS SIO2 en_US
dc.subject GLASSES en_US
dc.subject FORSTERITE en_US
dc.title In situ diffraction studies of magnesium silicate liquids en_US
dc.contributor.pbl Materials Research en_US
dc.contributor.pbl Institute of Mathematics & Physics (ADT) en_US

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