We report on an infrared study on the undoped compound BaFe2As2 as a function of both pressure (up to about 10 GPa) at three temperatures (300, 160, and 110 K). The evolution with pressure and temperature of the optical conductivity shows that, by increasing pressure, the mid-infrared absorptions associated with magnetic order are lowered while the Drude term increases, indicating the evolution towards a conventional metallic state. We evaluate the spectral weight dependence on pressure comparing it to that previously found upon doping. The whole optical results indicate that lattice modifications can not be recognized as the only parameter determining the low-energy electrodynamics in these compounds.
@article{arxiv.1306.1352,
title = {Electrodynamics of BaFe2As2 from infrared measurements under pressure},
author = {L. Baldassarre and A. Perucchi and P. Postorino and S. Lupi and C. Marini and L. Malavasi and J. Jiang and J. D. Weiss and E. E. Hellstrom and I. Pallecchi and P. Dore},
journal= {arXiv preprint arXiv:1306.1352},
year = {2013}
}