Electrical properties and behaviors of cuprous oxide cubes under high pressure.
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.
State Key Laboratory for Superhard Materials, Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
Cai-Long
CL
Liu
Yong-Ming
YM
Sui
Wan-Bin
WB
Ren
Bo-Heng
BH
Ma
Yan
Y
Li
Ning-Ning
NN
Su
Qing-Lin
QL
Wang
Yu-Qiang
YQ
Li
Jun-Kai
JK
Zhang
Yong-Hao
YH
Han
Yan-Zhang
YZ
Ma
Chun-Xiao
CX
Gao