The structure of liquid Sn was studied by neutron scattering experiments in the widest temperature range that was ever performed. Though, on increasing temperature, the existence of the shoulder in the structure factor, S(Q), becomes less clear in the change of the overall shape of the S(Q), the structure related to this shoulder seems to be present even at 1873 K. The first-principle molecular-dynamics ͑FPMD͒ simulation was performed for the first time for liquid Sn by using the cell size of 64 particles. The calculated results well reproduced S(Q) obtained by the neutron experiments. The angle distribution, g (3) (,r c ), was evaluated for the angle between vectors from centered atom to other two atoms in spheres of cutoff radii r c 's. The g (3) (,r c ) shows that, with the decrease of r c from 0.4 to 0.3 nm, a rather sharp peak around 60°disappears and only a broad peak around 100°remains; the former peak may be derived from the feature of the closely packed structures and the latter one is close to the tetrahedral angle of 109°. In addition, the coordination number, n, of liquid Sn counted within the sphere of r c ϭ0.3 nm is found to be 2-3 and does not change with the increase of temperature even up to 1873 K. These facts indicate that at least the fragment of the tetrahedral unit may be essentially kept even at 1873 K for liquid Sn. For comparison, the FPMD simulation was performed for the first time also for liquid Pb. No sign of the existence of the tetrahedral structure was observed for liquid Pb. Unfortunately, the self-diffusion coefficients, D's, obtained from this FPMD for liquid Sn do not agree with those obtained by the microgravity experiments though the structure factors, S(Q)'s, are well reproduced. To remove the limitation of the small cell size of the FPMD, the classical molecular-dynamics simulations with a cell size of 2197 particles were performed by incorporating the present experimental structural information of liquid Sn. Obtained D's are in good agreement with the microgravity data.

A 2-mm-diameter glass sphere of ferroelectric BaTi2O5 was fabricated from melt using containerless processing. The glass structure was analyzed by high-energy X-ray diffraction using an incident photon energy of 113.5 keV, indicating that distorted Ti−O polyhedra, with average coordination number (N Ti - O) of approximately 5, presented in the glass. Above the glass transition temperature (972 K), three successive phase transitions, from glass to a metastable α phase at 972 K, then to a metastable β phase at 1038 K, and finally to a stable monoclinic γ phase above 1100 K, were observed. At the crystallization temperature of the α phase, the permittivity jumped instantaneously by more than 1 order of magnitude, reaching a peak of 1.4 × 107. This interesting phenomenon, occurring near the crystallization temperature, has important technical implications for obtaining an excellent dielectric glass−ceramic through controlled crystallization of BaTi2O5 glass.