Electrical Properties and Behaviors of Cuprous Oxide Cubes under High Pressure

Abstract

An accurate in situ electrical resistivity measurement of cuprous oxide cubes has been conducted in a diamond anvil cell at room temperature with pressures up to 25 GPa. The abnormal electrical resistivity variation found at 0.7-2.2 GPa is attributed to the phase transformation from a cubic to a tetragonal structure. Three other discontinuous changes in the electrical resistivity are observed around 8.5, 10.3, and 21.6 GPa, corresponding to the phase transitions from tetragonal to pseudocubic to hexagonal to another hexagonal phase, respectively. The first-principles calculations illustrate that the electrical resistivity decrease of the tetragonal phase is not related to band-gap shrinkage but related to a higher quantity of electrons excited from strain-induced states increasing in band gap with increasing pressure. The results indicate that the Cu(2)O cubes begin to crush at about 15 GPa and completely transform into nanocrystalline at 25 GPa.

Anomalous semiconducting behavior on VO2 under high pressure

“…Hence we infer that the phase transition of VO 2 have a big possibility to be reversible. 29,30 However, in situ XRD experiments should be done to give direct evidence in the future.…”

Effects of high pressure on the lattice structure and electrical transport properties of BiOI

“…It is well-known that the pressure-induced disruption of cubes can produce abundant boundaries and microstrains in the sample, adding additional energy levels into the band gap and increasing the concentration of free charge carriers. 27,32 The inverse trend of the relaxation frequency of the grain and grain boundaries with pressure indicates a negative correlation between the relaxation time and pressure.…”

In situelectrical resistance and activation energy of solid C60under high pressure

“…Generally, the structure transitions of a material can affect its electrical properties. [17] At ambient conditions and high pressure, the pressure-induced phase transitions have been well studied before. The results indicated that there is no sign of phase transitions at 8 GPa and the C 60 cages collapse and form an amorphous phase of carbon at 16-20 GPa.…”