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Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-δ}$

P. Zheng·N. L. Wang·J. L. Luo·R. Jin·D. Mandrus
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Abstract

We present optical conductivity spectra for $Pb_{2}Ru_{2}O_{7-δ}$ 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 $t_{2g}$ bands with different plasma frequencies and scattering rates. The high frequency broad absorption may be contributed by two interband transitions: from occupied Ru $t_{2g}$ states to empty $e_{g}$ bands and from the fully filled O 2p bands to unoccupied Ru $t_{2g}$ states.

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P. Zheng, N. L. Wang, J. L. Luo, R. Jin, D. Mandrus. 2003-12-28. Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-δ}$. https://doi.org/10.1103/physrevb.69.193102

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