Pressure-induced metallization and amorphization inVO2(A)nanorods

Pressure-induced metallization of silane.

There is a great interest in electronic transitions in hydrogen-rich materials under extreme conditions. It has been recently suggested that the group IVa hydrides such as methane (CH(4)), silane (SiH(4)), and germane (GeH(4)) become metallic at far lower pressures than pure hydrogen at equivalent densities because the hydrogen is chemically compressed in group IVa hydride compounds. Here we re...

Pressure-induced metallization in Mg2Si

Mg2Si with narrow band gap has attracted increasing interest for its great potential applications. Theoretical calculations have predicted the metallization of Mg2Si under high pressure. In this work, the electrical resistance and Raman spectrum measurements of semiconducting Mg2Si were performed to investigate the metallization of Mg2Si by using diamond anvil cells and strip opposite anvils. A...

Pressure-induced metallization in solid boron

Different phases of solid boron under high pressure are studied by first principles calculations. The α-B12 structure is found to be stable up to 270 GPa. Its semiconductor band gap (1.72 eV) decreases continuously to zero around 160 GPa, where the material transforms to a weak metal. The metallicity, as measured by the density of states at the Fermi level, enhances as the pressure is further i...

Pressure-induced structural evolution and amorphization in Eu3Ga5O12

A New Phase and Pressure Induced Amorphization in Silica

Using first principles variable cell shape molecular dynamics, we predict a new structure for silica. This structure results from annealing a-quartz at pressures near a major phonon instability. The new phase is obtained by rotations of SiO4 tetrahedra producing edge-sharing SiO6 octahedra and SiO5 cuboids. This type of mechanism was proposed to account for structural transitions in silicate me...