Infrared study on CeSb under high pressures

The optical reflectivity spectra (R(ω)) of CeSb have been measured at high pressures to investigate the origin of the physical properties appearing under pressures. At 300 K, the pressure dependence of R(ω) revealed that the carrier density proportionally increases with increasing pressure up to 2.5 GPa. At lower temperature, the R(ω) spectrum drastically changes with both temperature and pressure due to the complex magnetic phase diagram. Especially, at 2.5 GPa and 30 K, the R(ω) intensity below 0.2 eV decreases, on the contrary that at around 0.3 eV increases. This result suggests that the density of states near the Fermi level decreases and shifts to the high-energy side