Cs2HBr4: amorphization under pressure

Picosecond amorphization of SiO2 stishovite under tension

It is extremely difficult to realize two conflicting properties-high hardness and toughness-in one material. Nano-polycrystalline stishovite, recently synthesized from Earth-abundant silica glass, proved to be a super-hard, ultra-tough material, which could provide sustainable supply of high-performance ceramics. Our quantum molecular dynamics simulations show that stishovite amorphizes rapidly...

A Novel High-Density Phase and Amorphization of Nitrogen-Rich 1H-Tetrazole (CH2N4) under High Pressure

The high-pressure behaviors of nitrogen-rich 1H-tetrazole (CH2N4) have been investigated by in situ synchrotron X-ray diffraction (XRD) and Raman scattering up to 75 GPa. A first crystalline-to-crystalline phase transition is observed and identified above ~3 GPa with a large volume collapse (∼18% at 4.4 GPa) from phase I to phase II. The new phase II forms a dimer-like structure, belonging to P...

Atomic-scale mechanism for pressure-induced amorphization of b-eucryptite

We present here a reactive force field based metadynamics study of pressure-induced amorphization in b-eucryptite, a lithium aluminum silicate that exhibits negative thermal expansion, i.e., volumetric contraction upon heating. From our simulations, we found that b-eucryptite amorphizes under a moderate applied pressure of 3 GPa. A careful inspection of the amorphous phase showed that it contai...

Pressure-induced structural evolution and amorphization in Eu3Ga5O12

Pressure-induced amorphization in the nanoindentation of single crystalline silicon

Large-scale molecular dynamics simulations of nanoindentation on a (100) oriented silicon surface were performed to investigate the mechanical behavior and phase transformation of single crystalline silicon. The direct crystalline-to-amorphous transformation is observed during the nanoindentation with a spherical indenter as long as the applied indentation strain or load is large enough. This a...