1202.3007 (H. Okamura et al.)

Pressure suppression of unconventional charge-density-wave state in
PrRu4P12 studied by optical conductivity    [PDF]

H. Okamura, N. Ohta, A. Takigawa, I. Matsutori, K. Shoji, K. Miyata, M. Matsunami, H. Sugawara, C. Sekine, I. Shirotani, H. Sato, T. Moriwaki, Y. Ikemoto, Z. Liu, G. L. Carr

Optical conductivity [s(w)] of PrRu4P12 has been studied under high pressure
to 14 GPa, at low temperatures to 8 K, and at photon energies between 12
meV-1.1 eV. s(w) was derived from the infrared reflectance spectra measured
with diamond anvil cell and infrared synchrotron radiation source. The energy
gap in s(w) at ambient pressure, caused by a metal-insulator transition due to
an unconventional charge-density-wave (CDW) formation at 63 K, is gradually
filled in with increasing pressure to 10 GPa. At 14 GPa, s(w) shows a
pronounced Drude-type component due to free carriers, without an energy gap.
This result demonstrates that the insulating CDW state has been suppressed
under high pressure, which is consistent with a previous resistivity study
under pressure. The evolution of electronic structure with pressure are
discussed in terms of the hybridization between the 4f and conduction
electrons.

View original: http://arxiv.org/abs/1202.3007