We investigate the calorimetric liquid-glass transition by performing simulations of a binary Lennard-Jones mixture in one through four dimensions. Starting at a high temperature, the systems are cooled to T = 0 and heated back to the ergodic liquid state at constant rates. Glass transitions are observed in two, three and four dimensions as a hysteresis between the cooling and heating curves. This hysteresis appears in the energy and pressure diagrams, and the scanning rate dependence of the area and height of the hysteresis can be described using power laws. The one-dimensional system does not experience a glass transition but its specific heat curve resembles the shape of the D≥2 results in the supercooled liquid regime above the glass transition. As D increases, the radial distribution functions reflect reduced geometric constraints. Nearest neighbor distances become smaller with increasing D due to interactions between nearest and next-nearest neighbors. Simulation data for the glasses are compared with crystal and melting data obtained with a Lennard-Jones system with only one type of particle and we find that with increasing D crystallization becomes increasingly more difficult.

B2–2xO3–2xH2x glasses were prepared by quenching the melt contained in sealed tubes. The glass-forming range extends from x = 0 to 0.50 (equal to the stoichiometry of metaboric acid, HBO2). The glasses were characterized by differential scanning calorimetry and x-ray scattering. With increasing water content, the glass-transition temperature, Tg, decreases from 553 to 333 K. The specific heat of water-rich samples shows an unusual peak just above Tg. The origin of this peak, which is seen upon heating and cooling, has not been identified. Unlike the composition dependence of Tg, the x-ray structure factors depend for the most part linearly on the composition. In analogy with the crystalline layer compounds α-HBO2 and B(OH)3, the x-ray scattering data show evidence for layering in the medium-range order of water-rich glasses.