Double roller quenching of Li2B204(0.9)-LiFe5Og(0.1) has been performed with various melt temperatures and roller • speeds .The changes in physical properties or in the devitrification process of the amorphous samples are shown to be related to the LiFejOg content variations or to the Fe^ appearance but not to structural changes of the amorphous state due to preparation processes

Uniformly-sized, single-crystal alpha-quartz nanospheres have been synthesized at 200 °C and 15 atm under continuous stirring starting from uniform, amorphous Stöber silica colloids and using NaCl and alkali hydroxide as mineralizers. Quartz nanosphere size is controlled by the colloid particle size via direct devitrification. Uniform, high-purity nanocrystalline quartz is important for underst...

Monodisperse single-crystalline α-cristobalite nanospheres have been synthesized by hydrocarbon-pyrolysis-induced carbon deposition on amorphous silica aerosol nanoparticles, devitrification of the coated silica at high temperature, and subsequent carbon removal by oxidation. The nanosphere size can be well controlled by tuning the size of the colloidal silica precursor. Uniform, high-purity na...

The heats of eutectic melting and devitrification, and the specific heats of the crystalline, glass, and liquid phases have been measured for a Ni,,Zr,, alloy. The data are used to calculate the Gibbs free-energy difference, AGAc , between the real glass and the crystal on an assumption that the liquid-glass transition is second order. The result shows that AG,, continuously increases as the te...

Introduction. About 100 m of impactites (suevitetype breccias) have been drilled at the ICDP drill site Yax-1 within the Chicxulub impact structure (see [1] for more information). Post-impact hydrothermal alteration including alkali metasomatism and devitrification of impact melt glass has significantly modified the mineralogy and chemistry of the impact breccia lithologies. Hydrothermal altera...