We present optical conductivity spectra for Pb2Ru2O7−δ single crystal at different temperatures. Among reported pyrochlore ruthenates, this compound exhibits metallic behavior in a wide temperature range and has the least resistivity. At low frequencies, the optical spectra show typical Drude responses, but with a knee feature around 1000 \cm. Above 20000 \cm, a broad absorption feature is observed. Our analysis suggests that the low frequency responses can be understood from two Drude components arising from the partially filled Ru t2g bands with different plasma frequencies and scattering rates. The high frequency broad absorption may be contributed by two interband transitions: from occupied Ru t2g states to empty eg bands and from the fully filled O 2p bands to unoccupied Ru t2g states.
@article{arxiv.cond-mat/0312662,
title = {Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-{\delta}}$},
author = {P. Zheng and N. L. Wang and J. L. Luo and R. Jin and D. Mandrus},
journal= {arXiv preprint arXiv:cond-mat/0312662},
year = {2009}
}