Unusual structure in vitreous forsterite synthesized by an aero-acoustic levitation technique

Kohara, Shinji*; Suzuya, Kentaro; Takeuchi, Ken*

Nihon Maikurogurabiti Oyo Gakkai-Shi, 22(2), p.100 - 104, 2005/04

Forsterite MgSiO exhibits an orthorhombic structure consisted of two kinds of MgO octahedra. Given only 33.3 mol% of SiO in the material, the SiO tetrahedra are isolated within the framework, sharing the O-O bonds with the common edges of the MgO octahedra. If forsterite can be vitrified, an interesting question concerning the glass structure arises because there is insufficient glass forming SiO to establish the corner-sharing SiO tetrahedral network needed in conventional silicate glasses. A bulk MgSiO glass was synthesized using an aero-acoustic levitation technique and to determine the short- to intermediate-range structure by a combined high-energy X-ray and neutron diffraction and reverse Monte Carlo computer simulation. Interestingly, we found that the role of network former is largely taken on by corner- and edge-sharing ionic magnesium species that adopt 4-, 5- and 6-coordination with oxygen.