Observation of charge ordering state in LiV2O4 investigated by optical study

Abstract

We have been investigated the electronic states of LiV2O4 under high pressures and low temperatures analyzed by optical study using an infrared microscope. The optical conductivities derived from reflectivities clearly exhibit the change from a metallic state at ambient pressure to an insulating state at 13 GPa with the pseudo gap of Δ ∼ 0.5 eV at the low temperature of 40 K. The Drude response observed at ambient pressure declines at high pressures even at 300 K. A softening phenomenon of a residual ray band structure is verified through the temperature change from 300 K to 40 K at 13 GPa.