Ice I without stacking disorder by evacuating hydrogen from hydrogen hydrate.

Water freezes below 0 °C at ambient pressure ordinarily to ice I, with hexagonal stacking sequence. Under certain conditions, ice with a cubic stacking sequence can also be formed, but ideal ice I without stacking-disorder has never been formed until recently. Here we demonstrate a route to obtain ice I without stacking-disorder by degassing hydrogen from the high-pressure form of hydrogen hydrate, C, which has a host framework isostructural with ice I.

Compositional redistribution in CaO-AlO-SiO glass induced by the migration of a steel microsphere due to continuous-wave-laser irradiation.

A high-power continuous-wave (CW) laser was used to move a steel microsphere through a CaO-AlO-SiO glass block at room temperature along a trajectory toward the laser source. A compositional analysis revealed that the CaO concentration in the glass decreased at the center of the microsphere's trajectory but increased in the area adjacent to it; the SiO concentration showed an opposite trend while the AlO concentration did not change. Further, the compositional difference between the center and the area adjacent to the microsphere trajectory depends on the velocity of the microsphere, which is controllable by tuning the laser power.

Partially ordered state of ice XV.

Most ice polymorphs have order-disorder "pairs" in terms of hydrogen positions, which contributes to the rich variety of ice polymorphs; in fact, three recently discovered polymorphs- ices XIII, XIV, and XV-are ordered counter forms to already identified disordered phases. Despite the considerable effort to understand order-disorder transition in ice crystals, there is an inconsistency among the various experiments and calculations for ice XV, the ordered counter form of ice VI, i.e.