C. Landron et al., Liquid alumina: detailed atomic coordination determined from neutron diffraction data using empirical potential structure refinement, PHYS REV L, 86(21), 2001, pp. 4839-4842
The neutron scattering structure factor SN(e) for a 40 mg drop of molten al
umina (Al2O3) held at 2500 K, using a laser-heated aerodynamic levitation f
urnace, is measured for the first time. A 1700 atom model of liquid alumina
is generated from these data using the technique of empirical potential st
ructural refinement. About 62% of the aluminum sites are 4-fold coordinated
, matching the mostly triply coordinated oxygen sites, but some 24% of the
aluminum sites are 5-fold coordinated. The octahedral aluminum sites found
in crystalline alpha -Al2O3 occur only at the 2% level in liquid alumina.