Can I read In-gap state and effect of light illumination in CuIr$ 2$S$ 4$ probed by photoemission spectroscopy on EtoBox?

In-gap state and effect of light illumination in CuIr$ 2$S$ 4$ probed by photoemission spectroscopy by Takubo, K.; Mizokawa, T.; Matsumoto, N.; Nagata, S. is a scholarly article available to read on EtoBox.

What is In-gap state and effect of light illumination in CuIr$ 2$S$ 4$ probed by photoemission spectroscopy about?

We have studied disorder-induced in-gap states and effect of light illumination in the insulating phase of spinel-type CuIr$_2$S$_4$ using ultra-violet photoemission spectroscopy (UPS). The Ir$^{3+}$/Ir$^{4+}$ charge-ordered gap appears below the metal-insulator transition temperature. However, in the insulating phase, in-gap spectral features with $softgap$ are observed in UPS just below the Fermi level ($E_F$), corresponding to the variable range hopping transport observed in resistivity. The spectral weight at $E_F$ is not increased by light illumination, indicating that the Ir$^{4+}$-Ir$^{4+}$ dimer is very robust although the long-range octamer order would be destructed by the photo-excitation. Present results suggest that the Ir$^{4+}$-Ir$^{4+}$ bipolaronic hopping and disorder effects are responsible for the conductivity of CuIr$_2$S$_4$.

Author

Takubo, K.; Mizokawa, T.; Matsumoto, N.; Nagata, S.

Published

2008

Language

EN