Revisiting optical properties of MgB₂ with a high-quality sample prepared by a HPCVD method.

ABSTRACT: We investigated a high-quality MgB₂ thin film with a thickness of ~1000 nm on an Al₂O₃ substrate using optical spectroscopy. We measured the reflectance spectra of the film at various temperatures both below, and above, the superconducting transition temperature, T _c   [Formula: see text] 40 K. An earlier study showed that when the sample surface is exposed to air the optical properties of the surface change immediately, however, the saturated change is negligibly small in the far-infrared region. The optical conductivity spectrum in the normal state shows two (narrow and broad) Drude modes, with the narrow Drude mode being dominant in the low frequency region below 1000 cm^-1. Our study, which uses a good-quality sample, provides more

SUBMITTER: Seo YS 

PROVIDER: S-EPMC5567084 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature