We present the optical reflectance and conductivity spectra for non-oxide antiperovskite superconductor MgCNi3 at different temperatures. The reflectance drops gradually over a large energy scale up to 33,000 cm−1, with the presence of several wiggles. The reflectance has slight temperature dependence at low frequency but becomes temperature independent at high frequency. The optical conductivity shows a Drude response at low frequencies and four broad absorption features in the frequency range from 600 cm−1 to 33,000 cm−1. We illustrate that those features can be well understood from the intra- and interband transitions between different components of Ni 3d bands which are hybridized with C 2p bands. There is a good agreement between our experimental data and the first-principle band structure calculations.
@article{arxiv.cond-mat/0507599,
title = {Optical properties of $MgCNi_3$ in the normal state},
author = {P. Zheng and J. L. Luo and G. T. Liu and Y. L. Zhang and R. C. Yu and C. Q. Jin and N. L. Wang and M. Q. Tan},
journal= {arXiv preprint arXiv:cond-mat/0507599},
year = {2009}
}