We have investigated a metal-insulator transition in a 4d-electron system R2Mo2O7 (R = Sm and Y) by means of optical spectroscopy. The electronic structure is reconstructed over an energy range of several electron volt upon the transition. The insulating Y2Mo2O7 compound shows an optical gap of ca. 0.1 eV at 10 K and the temperature dependence of optical conductivity is rather weak. On the other hand, metallic Sm2Mo2O7 exhibits a tiny Drude-peak and strong mid-infrared absorption at 10 K and the conductivity strongly depends on temperature. These observations demonstrate the importance of correlation effect also in 4d-electron system with a wider bandwidth than 3d-electron system.
|Number of pages||5|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2002 Mar 15|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics