Optical spectroscopy of the metal-insulator transition inNdNiO3

Autor: Yasuhiro Tokura, Jerry B. Torrance, Taka-hisa Arima, Takuro Katsufuji, Yoichi Okimoto
Rok vydání: 1995
Předmět:
Zdroj: Physical Review B. 51:4830-4835
ISSN: 1095-3795
0163-1829
DOI: 10.1103/physrevb.51.4830
Popis: We report optical measurements of ${\mathrm{NdNiO}}_{3}$ that undergo a phase transition from a paramagnetic metal to an antiferromagnetic insulator at 200 K (=${\mathit{T}}_{\mathit{c}}$). The opening of a charge gap is observed in the optical conductivity spectrum [\ensuremath{\sigma}(\ensuremath{\omega})] below ${\mathit{T}}_{\mathit{c}}$, and the missing spectral weight is distributed over the energy region above 0.3 eV. The evolution of the gap below ${\mathit{T}}_{\mathit{c}}$ is rather gradual with temperature, in contrast to sharp changes of lattice parameters and resistivity at ${\mathit{T}}_{\mathit{c}}$. Such a feature in the \ensuremath{\sigma}(\ensuremath{\omega}) spectrum of ${\mathrm{NdNiO}}_{3}$ is characteristic of a spin-density-wave (SDW) state, though the peak energy (\ensuremath{\sim}0.4 eV) of the \ensuremath{\sigma}(\ensuremath{\omega}) spectrum is considerably larger than that predicted by a simple SDW theory. The effect of electron correlation is discussed on the basis of the \ensuremath{\sigma}(\ensuremath{\omega}) spectra.
Databáze: OpenAIRE