Emergence of electronic conduction in bismuth oxide eletrolyte under high pressure

Abstract

The ionic transport properties of bismuth oxide (Bi 2 O 3 ) were investigated under high pressures with impedance spectrum and Raman spectrum measurements. It was found that Bi 2 O 3 is a pure ionic conductor below 9.0 GPa. Its pressure-dependent ionic conduction is determined by the diffusion rate of O 2− ions. Above 9.0 GPa, the number of O 2− ions that participate in electrical transportation are reduced rapidly by the pressureinduced distortion of crystal lattice, which becomes the essential factor to affect the ionic conduction. Most importantly, electronic conduction began to appear in the transportation process and coexist with the ionic conduction at 9.0 GPa indicating a few of originally localized electrons are involved in the electrical transportation due to the enhancement in distorted intension of Bi polyhedrons. Meanwhile, from the impedance spectra studies, it was also known that the electrical transport behaviors of Bi 2 O 3 can be tuned by the frequency of input signals. At high frequencies, Bi 2 O 3 behaves like an ionic solid electrolyte, but at low frequencies, it behaves like an electronic resistor.

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

“…Bi 2 O 3 behaves like an ionic solid electrolyte at high frequencies but as an electronic resistor at low frequencies. 22 These studies prove that research using high pressure can reveal more novel properties of materials and provide new possibilities for expanding and improving the application of materials. A systematic study of the pressure effects on BiOI's electrical transport properties would better reveal the potential and correlate pressure with the further exploration of BiOX semiconductors.…”